U.S. patent application number 12/359998 was filed with the patent office on 2009-07-30 for systems and methods for configuration driven rewrite of ssl vpn clientless sessions.
Invention is credited to Puneet Agarwal, Prakash Khemani, Vamsi Korrapatti, Rajiv Mirani, Anoop Reddy, Srinivasan Thirunarayanan.
Application Number | 20090193126 12/359998 |
Document ID | / |
Family ID | 40548586 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090193126 |
Kind Code |
A1 |
Agarwal; Puneet ; et
al. |
July 30, 2009 |
SYSTEMS AND METHODS FOR CONFIGURATION DRIVEN REWRITE OF SSL VPN
CLIENTLESS SESSIONS
Abstract
The present disclosure provides solutions for an enterprise
providing services to a variety of clients to enable the client to
use the resources provided by the enterprise by modifying URLs
received and the URLs from the responses from the servers to the
client's requests before forwarding the requests and the responses
to the intended destinations. An intermediary may identify an
access profile for a clients' request to access a server via a
clientless SSL VPN session. The intermediary may detect one or more
URLs in content served by the server in response to the request
using one or more regular expressions of the access profile. The
intermediary may rewrite or modify, responsive to detecting, the
one or more detected URLs in accordance with a URL transformation
specified by one or more rewrite policies of the access profile.
The response with modified URLs may be forwarded to the client.
Inventors: |
Agarwal; Puneet; (Bangalore,
IN) ; Thirunarayanan; Srinivasan; (Chennai, TH)
; Korrapatti; Vamsi; (Sunnyvale, CA) ; Khemani;
Prakash; (San Jose, CA) ; Mirani; Rajiv; (San
Jose, CA) ; Reddy; Anoop; (San Jose, CA) |
Correspondence
Address: |
CHOATE, HALL & STEWART / CITRIX SYSTEMS, INC.
TWO INTERNATIONAL PLACE
BOSTON
MA
02110
US
|
Family ID: |
40548586 |
Appl. No.: |
12/359998 |
Filed: |
January 26, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61023848 |
Jan 26, 2008 |
|
|
|
Current U.S.
Class: |
709/228 |
Current CPC
Class: |
H04L 63/0272 20130101;
H04L 29/08846 20130101; H04L 63/20 20130101; H04L 63/0281 20130101;
H04L 67/2814 20130101; H04L 63/105 20130101; H04L 67/14 20130101;
H04L 63/166 20130101; H04L 67/02 20130101 |
Class at
Publication: |
709/228 |
International
Class: |
G06F 15/173 20060101
G06F015/173 |
Claims
1. A method for rewriting by an intermediary content transmitted
via a clientless secure socket layer virtual private network (SSL
VPN) session between a client and a server, the method comprising:
a) identifying, by an intermediary, an access profile for a request
from a client to access a server via a clientless SSL VPN session
established between the client and the server, the access profile
comprising a first rewrite policy for rewriting uniform resource
locators (URLs) and one or more regular expressions to detect one
or more URLs in content served by the server; b) detecting, by the
intermediary responsive to the one or more regular expressions of
the access profile, one or more URLs in content served by the
server in response to the request; and c) rewriting, by the
intermediary responsive to detecting, the one or more detected URLs
in accordance with a URL transformation specified by the first
rewrite policy.
2. The method of claim 1, wherein step (a) further comprises
identifying by the intermediary the access profile comprising a
plurality of regular expressions, each of the plurality of regular
expressions for detecting one or more URLs in a type of content of
a plurality of different types of content and step (b) further
comprises identifying one or more types of content in the content
served by the server.
3. The method of claim 1, wherein step (a) further comprises
identifying by the intermediary the access profile comprising a
regular expression for detecting a URL in content comprising
JavaScript.
4. The method of claim 1, wherein step (a) further comprises
identifying by the intermediary the access profile comprising a
regular expression for detecting a URL in content comprising
Extensible Markup Language (XML).
5. The method of claim 1, wherein step (a) further comprises
identifying by the intermediary the access profile comprising a
regular expression for detecting a URL in content comprising
Cascading Style Sheets (CSS).
6. The method of claim 1, wherein step (b) further comprises
detecting, by the intermediary responsive to a first regular
expression identified by the access profile, one or more uniform
resource locators (URLs) in a first type of content of the response
and detecting, responsive to a second regular expression identified
by the access profile, one or more URLs in a second type of content
of the response.
7. The method of claim 1, wherein step (c) further comprises
rewriting, by the intermediary, portions of JavaScript of the
content in accordance with a JavaScript transformation specified by
a second rewrite policy associated with the identified access
profile.
8. The method of claim 1, wherein step (a) further comprising
identifying, by the intermediary, the access profile comprising a
second rewrite policy to rewrite a header of the request header and
rewriting the header of the request in accordance with a
transformation specified by the rewrite policy prior to
transmission to the server.
9. The method of claim 1, wherein step (a) further comprising
identifying, by the intermediary, the access profile comprising a
second rewrite policy to rewrite a header of the response and step
(c) further comprises rewriting the header of the response in
accordance with a transformation specified by the second rewrite
policy prior to transmission to the client.
10. The method of claim 1, wherein step (a) comprises identifying,
by the intermediary, the access profile from a plurality of access
profiles based on determining an application requested via the
request.
11. An intermediary for rewriting content transmitted via a
clientless secure socket layer virtual private network (SSL VPN)
session between a client and a server, the intermediary comprising:
a policy engine for identifying an access profile for a request
from a client to access a server via a clientless SSL VPN session
established between the client and the server, the access profile
comprising a first rewrite policy for rewriting uniform resource
locators (URLs) and one or more regular expressions to detect one
or more URLs in content served by the server; a detector for
detecting responsive to the one or more regular expressions of the
access profile, one or more URLs in content served by the server in
response to the request; and a rewriter for rewriting responsive to
the detector the one or more detected URLs in accordance with a URL
transformation specified by the first rewrite policy.
12. The intermediary of claim 11, wherein the policy engine
identifies the access profile comprising a plurality of regular
expressions, each of the plurality of regular expressions for
detecting one or more URLs in a type of content of a plurality of
different types of content and the detector determines one or more
types of content in the content served by the server.
13. The intermediary of claim 11, wherein the policy engine
identifies the access profile comprising a regular expression for
detecting a URL in content comprising JavaScript.
14. The intermediary of claim 11, wherein the policy engine
identifies the access profile comprising a regular expression for
detecting a URL in content comprising Extensible Markup Language
(XML).
15. The intermediary of claim 11, wherein the policy engine
identifies the access profile comprising a regular expression for
detecting a URL in content comprising Cascading Style Sheets
(CSS).
16. The intermediary of claim 11, wherein the detector detects
responsive to a first regular expression identified by the access
profile, one or more uniform resource locators (URLs) in a first
type of content of the response and detects responsive to a second
regular expression identified by the access profile, one or more
URLs in a second type of content of the response.
17. The intermediary of claim 11, wherein the rewriter rewrites
portions of JavaScript of the content in accordance with a
JavaScript transformation specified by a second rewrite policy
associated with the identified access profile.
18. The intermediary of claim 11, wherein the policy engine
identifies the access profile comprising a second rewrite policy to
rewrite a header of the request header and rewriting the header of
the request in accordance with a transformation specified by the
rewrite policy prior to transmission to the server.
19. The intermediary of claim 11, wherein the policy engine
identifies the access profile comprising a second rewrite policy to
rewrite a header of the response and the rewriter rewrites the
header of the response in accordance with a transformation
specified by the second rewrite policy prior to transmission to the
client.
20. A method for rewriting by an intermediary content transmitted
via a clientless secure socket layer virtual private network (SSL
VPN) session between a client and a server, the method comprising:
a) identifying, by an intermediary, an access profile for a
clientless SSL VPN session established between a client and a
server, the access profile comprising a plurality of rewrite
policies and a plurality of regular expressions, each of the
plurality of rewrite policies specify a transformation for a type
of content, and each of the plurality of regular expressions
specify a regular expression to detect uniform resource locators
(URLs) in each of a plurality of types of content; b) determining,
by the intermediary, the type of content served by the server in
response to the request; c) detecting, by the intermediary, one or
more URLs in the content based on the regular expression specified
for the determined type of content via the access profile; and d)
rewriting, by the intermediary, a portion of the content based on
the type of content and a rewrite policy from the plurality of
rewrite policies for the type of content.
Description
RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Application No. 61/023,848 filed on Jan. 26, 2008, incorporated
herein by reference.
FIELD OF THE INVENTION
[0002] The present application generally relates to data
communication networks. In particular, the present application
relates to systems and methods for policy control of SSL VPN
clientless access, fine grain policy driven rewrite of URLs during
SSL VPN clientless access, and configuration and policy driven
detection of embedded URLs in different content types served from a
server to a client during SSL VPN clientless access.
BACKGROUND OF THE INVENTION
[0003] A company or an enterprise may provide various services
across a network to serve a variety of clients. Some of these
clients may satisfy the security requirements of the enterprise
while others may access the resources of the enterprise from
networks, services or locations which may not be safe. The
enterprise may choose to allow all the clients to access the
resources, but may decide to protect sensitive information relating
the resources of the servers from some, or all, of the clients. In
one example, a client may request to access resources provided by a
server of the enterprise via a clientless secure socket layer
virtual private network (SSL VPN) session. The enterprise may
decide to deny the client access to the actual URLs of the
resources the client is accessing, while allowing the client to
access the resources requested.
BRIEF SUMMARY OF THE INVENTION
[0004] The present disclosure provides solutions to this and
similar problems that may enable the client to use the resources
provided by the enterprise servers while not being able to access
the URLs of the server. The enterprise may use rewrite policies of
access profiles associated with requests of the client to rewrite
or modify URLs of the client. The modified URLs from the client are
used to access the resources on the servers. Upon receiving
responses from the servers, the enterprise may rewrite or modify
the URLs of the responses using the rewrite policies to modify the
URLs prior to forwarding the responses to the client.
[0005] In some aspects, the present disclosure is related to
methods for rewriting, by an intermediary, content transmitted via
a clientless secure socket layer virtual private network (SSL VPN)
session between a client and a server. An intermediary may identify
an access profile for a request from a client to access a server
via a clientless SSL VPN session established between the client and
the server. The access profile may comprise a first rewrite policy
for rewriting uniform resource locators (URLs) and one or more
regular expressions to detect one or more URLs in content served by
the server. The intermediary may detect, responsive to the one or
more regular expressions of the access profile, one or more URLs in
content served by the server in response to the request. The
intermediary may rewrite, responsive to detecting, the one or more
detected URLs in accordance with a URL transformation specified by
the first rewrite policy.
[0006] In some embodiments, the intermediary may identify the
access profile comprising a plurality of regular expressions. Each
of the plurality of regular expressions may be for detecting one or
more URLs in a type of content of a plurality of different types of
content. The intermediary may identify one or more types of content
in the content served by the server. In some embodiments, the
intermediary identifies the access profile comprising a regular
expression for detecting a URL in content comprising JavaScript. In
some embodiments, the intermediary identifies the access profile
comprising a regular expression for detecting a URL in content
comprising Extensible Markup Language (XML). In further
embodiments, the intermediary identifies the access profile
comprising a regular expression for detecting a URL in content
comprising Cascading Style Sheets (CSS). In some embodiments, the
intermediary detects, responsive to a first regular expression
identified by the access profile, one or more uniform resource
locators (URLs) in a first type of content of the response. In
further embodiments, the intermediary detects, responsive to a
second regular expression identified by the access profile, one or
more URLs in a second type of content of the response.
[0007] The intermediary may rewrite portions of JavaScript of the
content in accordance with a JavaScript transformation specified by
a second rewrite policy associated with the identified access
profile. In some embodiments, the intermediary identifies the
access profile comprising a second rewrite policy to rewrite a
header of the request header. In further embodiments, the
intermediary rewrites the header of the request in accordance with
a transformation specified by the rewrite policy prior to
transmission to the server. The intermediary may identify the
access profile comprising a second rewrite policy to rewrite a
header of the response and rewrite the header of the response in
accordance with a transformation specified by the second rewrite
policy prior to transmission to the client. The intermediary may
identify the access profile from a plurality of access profiles
based on determining an application requested via the request.
[0008] In some aspects, the present disclosure is related to an
intermediary or a system for rewriting content transmitted via a
clientless secure socket layer virtual private network (SSL VPN)
session between a client and a server. A policy engine may identify
an access profile for a request from a client to access a server
via a clientless SSL VPN session established between the client and
the server. The policy engine may be of an intermediary. The access
profile may comprise a first rewrite policy for rewriting uniform
resource locators (URLs) and one or more regular expressions to
detect one or more URLs in content served by the server. A detector
may detect, responsive to the one or more regular expressions of
the access profile, one or more URLs in content served by the
server in response to the request. The detector may be of the
intermediary. A rewriter may rewrite, responsive to the detector,
the one or more detected URLs in accordance with a URL
transformation specified by the first rewrite policy. The rewriter
may be of the intermediary.
[0009] In some embodiments, the policy engine identifies the access
profile comprising a plurality of regular expressions. Each of the
plurality of regular expressions may be for detecting one or more
URLs in a type of content of a plurality of different types of
content. The detector may determine one or more types of content in
the content served by the server. In some embodiments, the policy
engine identifies the access profile comprising a regular
expression for detecting a URL in content comprising JavaScript. In
further embodiments, the policy engine identifies the access
profile comprising a regular expression for detecting a URL in
content comprising Extensible Markup Language (XML). In some
embodiments, the policy engine identifies the access profile
comprising a regular expression for detecting a URL in content
comprising Cascading Style Sheets (CSS). In yet other embodiments,
the detector detects, responsive to a first regular expression
identified by the access profile, one or more uniform resource
locators (URLs) in a first type of content of the response and
detects responsive to a second regular expression identified by the
access profile, one or more URLs in a second type of content of the
response. In some embodiments, the rewriter rewrites portions of
JavaScript of the content in accordance with a JavaScript
transformation specified by a second rewrite policy associated with
the identified access profile. In further embodiments, the policy
engine identifies the access profile comprising a second rewrite
policy to rewrite a header of the request header and rewriting the
header of the request in accordance with a transformation specified
by the rewrite policy prior to transmission to the server. In some
embodiments, the policy engine identifies the access profile
comprising a second rewrite policy to rewrite a header of the
response and the rewriter rewrites the header of the response in
accordance with a transformation specified by the second rewrite
policy prior to transmission to the client.
[0010] In some aspects, the present disclosure is related to a
method for rewriting by an intermediary content transmitted via a
clientless secure socket layer virtual private network (SSL VPN)
session between a client and a server. An intermediary may identify
an access profile for a clientless SSL VPN session established
between a client and a server. The access profile may comprise a
plurality of rewrite policies and a plurality of regular
expressions. Each of the plurality of rewrite policies may specify
a transformation for a type of content. Each of the plurality of
regular expressions may specify a regular expression to detect
uniform resource locators (URLs) in each of a plurality of types of
content. The intermediary may determine the type of content served
by the server in response to the request. The intermediary may
detect one or more URLs in the content based on the regular
expression specified for the determined type of content via the
access profile. The intermediary may rewrite a portion of the
content based on the type of content and a rewrite policy from the
plurality of rewrite policies for the type of content.
BRIEF DESCRIPTION OF THE FIGURES
[0011] The foregoing and other objects, aspects, features, and
advantages of the invention will become more apparent and better
understood by referring to the following description taken in
conjunction with the accompanying drawings, in which:
[0012] FIGS. 1A, 1B and 1C are block diagrams of embodiments of a
network environment for a client to access a server via one or more
appliances;
[0013] FIG. 1D is a block diagram of an embodiment of an
environment for delivering a computing environment from a server to
a client via an appliance;
[0014] FIGS. 1E and 1F are block diagrams of embodiments of a
computing device;
[0015] FIG. 2A is a block diagram of an embodiment of an appliance
for processing communications between a client and a server;
[0016] FIG. 2B is a block diagram of another embodiment of an
appliance for optimizing, accelerating, load-balancing and routing
communications between a client and a server;
[0017] FIG. 3A and 3B are block diagrams of an embodiment of a
clientless virtual private network access to a server via the
appliance;
[0018] FIG. 4 is a block diagram of an embodiment of an appliance
between a client and a server performing URL rewrite;
[0019] FIG. 5 is a flow diagram of steps of an embodiment of a
method to perform URL rewriting on a client request;
[0020] FIG. 6 is a block diagram of embodiments of a server
response and a modified server response transmitted from a server
to a client through an appliance; and
[0021] FIG. 7 is a flow diagram of steps of an embodiment of a
method to perform URL rewriting on a server response.
[0022] The features and advantages of the present invention will
become more apparent from the detailed description set forth below
when taken in conjunction with the drawings, in which like
reference characters identify corresponding elements throughout. In
the drawings, like reference numbers generally indicate identical,
functionally similar, and/or structurally similar elements.
DETAILED DESCRIPTION OF THE INVENTION
A. Network and Computing Environment
[0023] Prior to discussing the specifics of embodiments of the
systems and methods of an appliance and/or client, it may be
helpful to discuss the network and computing environments in which
such embodiments may be deployed. Referring now to FIG. 1A, an
embodiment of a network environment is depicted. In brief overview,
the network environment comprises one or more clients 102a-102n
(also generally referred to as local machine(s) 102, or client(s)
102) in communication with one or more servers 106a-106n (also
generally referred to as server(s) 106, or remote machine(s) 106)
via one or more networks 104, 104' (generally referred to as
network 104). In some embodiments, a client 102 communicates with a
server 106 via an appliance 200.
[0024] Although FIG. 1A shows a network 104 and a network 104'
between the clients 102 and the servers 106, the clients 102 and
the servers 106 may be on the same network 104. The networks 104
and 104' can be the same type of network or different types of
networks. The network 104 and/or the network 104' can be a
local-area network (LAN), such as a company Intranet, a
metropolitan area network (MAN), or a wide area network (WAN), such
as the Internet or the World Wide Web. In one embodiment, network
104' may be a private network and network 104 may be a public
network. In some embodiments, network 104 may be a private network
and network 104' a public network. In another embodiment, networks
104 and 104' may both be private networks. In some embodiments,
clients 102 may be located at a branch office of a corporate
enterprise communicating via a WAN connection over the network 104
to the servers 106 located at a corporate data center.
[0025] The network 104 and/or 104' be any type and/or form of
network and may include any of the following: a point to point
network, a broadcast network, a wide area network, a local area
network, a telecommunications network, a data communication
network, a computer network, an ATM (Asynchronous Transfer Mode)
network, a SONET (Synchronous Optical Network) network, a SDH
(Synchronous Digital Hierarchy) network, a wireless network and a
wireline network. In some embodiments, the network 104 may comprise
a wireless link, such as an infrared channel or satellite band. The
topology of the network 104 and/or 104' may be a bus, star, or ring
network topology. The network 104 and/or 104' and network topology
may be of any such network or network topology as known to those
ordinarily skilled in the art capable of supporting the operations
described herein.
[0026] As shown in FIG. 1A, the appliance 200, which also may be
referred to as an interface unit 200 or gateway 200, is shown
between the networks 104 and 104'. In some embodiments, the
appliance 200 may be located on network 104. For example, a branch
office of a corporate enterprise may deploy an appliance 200 at the
branch office. In other embodiments, the appliance 200 may be
located on network 104'. For example, an appliance 200 may be
located at a corporate data center. In yet another embodiment, a
plurality of appliances 200 may be deployed on network 104. In some
embodiments, a plurality of appliances 200 may be deployed on
network 104'. In one embodiment, a first appliance 200 communicates
with a second appliance 200'. In other embodiments, the appliance
200 could be a part of any client 102 or server 106 on the same or
different network 104, 104' as the client 102. One or more
appliances 200 may be located at any point in the network or
network communications path between a client 102 and a server
106.
[0027] In some embodiments, the appliance 200 comprises any of the
network devices manufactured by Citrix Systems, Inc. of Ft.
Lauderdale Fla., referred to as Citrix NetScaler devices. In other
embodiments, the appliance 200 includes any of the product
embodiments referred to as WebAccelerator and BigIP manufactured by
F5 Networks, Inc. of Seattle, Wash. In another embodiment, the
appliance 205 includes any of the DX acceleration device platforms
and/or the SSL VPN series of devices, such as SA 700, SA 2000, SA
4000, and SA 6000 devices manufactured by Juniper Networks, Inc. of
Sunnyvale, Calif. In yet another embodiment, the appliance 200
includes any application acceleration and/or security related
appliances and/or software manufactured by Cisco Systems, Inc. of
San Jose, Calif., such as the Cisco ACE Application Control Engine
Module service software and network modules, and Cisco AVS Series
Application Velocity System.
[0028] In one embodiment, the system may include multiple,
logically-grouped servers 106. In these embodiments, the logical
group of servers may be referred to as a server farm 38. In some of
these embodiments, the serves 106 may be geographically dispersed.
In some cases, a farm 38 may be administered as a single entity. In
other embodiments, the server farm 38 comprises a plurality of
server farms 38. In one embodiment, the server farm executes one or
more applications on behalf of one or more clients 102.
[0029] The servers 106 within each farm 38 can be heterogeneous.
One or more of the servers 106 can operate according to one type of
operating system platform (e.g., WINDOWS NT, manufactured by
Microsoft Corp. of Redmond, Wash.), while one or more of the other
servers 106 can operate on according to another type of operating
system platform (e.g., Unix or Linux). The servers 106 of each farm
38 do not need to be physically proximate to another server 106 in
the same farm 38. Thus, the group of servers 106 logically grouped
as a farm 38 may be interconnected using a wide-area network (WAN)
connection or medium-area network (MAN) connection. For example, a
farm 38 may include servers 106 physically located in different
continents or different regions of a continent, country, state,
city, campus, or room. Data transmission speeds between servers 106
in the farm 38 can be increased if the servers 106 are connected
using a local-area network (LAN) connection or some form of direct
connection.
[0030] Servers 106 may be referred to as a file server, application
server, web server, proxy server, or gateway server. In some
embodiments, a server 106 may have the capacity to function as
either an application server or as a master application server. In
one embodiment, a server 106 may include an Active Directory. The
clients 102 may also be referred to as client nodes or endpoints.
In some embodiments, a client 102 has the capacity to function as
both a client node seeking access to applications on a server and
as an application server providing access to hosted applications
for other clients 102a-102n.
[0031] In some embodiments, a client 102 communicates with a server
106. In one embodiment, the client 102 communicates directly with
one of the servers 106 in a farm 38. In another embodiment, the
client 102 executes a program neighborhood application to
communicate with a server 106 in a farm 38. In still another
embodiment, the server 106 provides the functionality of a master
node. In some embodiments, the client 102 communicates with the
server 106 in the farm 38 through a network 104. Over the network
104, the client 102 can, for example, request execution of various
applications hosted by the servers 106a-106n in the farm 38 and
receive output of the results of the application execution for
display. In some embodiments, only the master node provides the
functionality required to identify and provide address information
associated with a server 106' hosting a requested application.
[0032] In one embodiment, the server 106 provides functionality of
a web server. In another embodiment, the server 106a receives
requests from the client 102, forwards the requests to a second
server 106b and responds to the request by the client 102 with a
response to the request from the server 106b. In still another
embodiment, the server 106 acquires an enumeration of applications
available to the client 102 and address information associated with
a server 106 hosting an application identified by the enumeration
of applications. In yet another embodiment, the server 106 presents
the response to the request to the client 102 using a web
interface. In one embodiment, the client 102 communicates directly
with the server 106 to access the identified application. In
another embodiment, the client 102 receives application output
data, such as display data, generated by an execution of the
identified application on the server 106.
[0033] Referring now to FIG. 1B, an embodiment of a network
environment deploying multiple appliances 200 is depicted. A first
appliance 200 may be deployed on a first network 104 and a second
appliance 200' on a second network 104'. For example a corporate
enterprise may deploy a first appliance 200 at a branch office and
a second appliance 200' at a data center. In another embodiment,
the first appliance 200 and second appliance 200' are deployed on
the same network 104 or network 104. For example, a first appliance
200 may be deployed for a first server farm 38, and a second
appliance 200 may be deployed for a second server farm 38'. In
another example, a first appliance 200 may be deployed at a first
branch office while the second appliance 200' is deployed at a
second branch office'. In some embodiments, the first appliance 200
and second appliance 200' work in cooperation or in conjunction
with each other to accelerate network traffic or the delivery of
application and data between a client and a server
[0034] Referring now to FIG. 1C, another embodiment of a network
environment deploying the appliance 200 with one or more other
types of appliances, such as between one or more WAN optimization
appliance 205, 205' is depicted. For example a first WAN
optimization appliance 205 is shown between networks 104 and 104'
and s second WAN optimization appliance 205' may be deployed
between the appliance 200 and one or more servers 106. By way of
example, a corporate enterprise may deploy a first WAN optimization
appliance 205 at a branch office and a second WAN optimization
appliance 205' at a data center. In some embodiments, the appliance
205 may be located on network 104'. In other embodiments, the
appliance 205' may be located on network 104. In some embodiments,
the appliance 205' may be located on network 104' or network 104''.
In one embodiment, the appliance 205 and 205' are on the same
network. In another embodiment, the appliance 205 and 205' are on
different networks. In another example, a first WAN optimization
appliance 205 may be deployed for a first server farm 38 and a
second WAN optimization appliance 205' for a second server farm
38'
[0035] In one embodiment, the appliance 205 is a device for
accelerating, optimizing or otherwise improving the performance,
operation, or quality of service of any type and form of network
traffic, such as traffic to and/or from a WAN connection. In some
embodiments, the appliance 205 is a performance enhancing proxy. In
other embodiments, the appliance 205 is any type and form of WAN
optimization or acceleration device, sometimes also referred to as
a WAN optimization controller. In one embodiment, the appliance 205
is any of the product embodiments referred to as WANScaler
manufactured by Citrix Systems, Inc. of Ft. Lauderdale, Fla. In
other embodiments, the appliance 205 includes any of the product
embodiments referred to as BIG-IP link controller and WANjet
manufactured by F5 Networks, Inc. of Seattle, Wash. In another
embodiment, the appliance 205 includes any of the WX and WXC WAN
acceleration device platforms manufactured by Juniper Networks,
Inc. of Sunnyvale, Calif. In some embodiments, the appliance 205
includes any of the steelhead line of WAN optimization appliances
manufactured by Riverbed Technology of San Francisco, Calif. In
other embodiments, the appliance 205 includes any of the WAN
related devices manufactured by Expand Networks Inc. of Roseland,
N.J. In one embodiment, the appliance 205 includes any of the WAN
related appliances manufactured by Packeteer Inc. of Cupertino,
Calif. such as the PacketShaper, iShared, and SkyX product
embodiments provided by Packeteer. In yet another embodiment, the
appliance 205 includes any WAN related appliances and/or software
manufactured by Cisco Systems, Inc. of San Jose, Calif., such as
the Cisco Wide Area Network Application Services software and
network modules, and Wide Area Network engine appliances.
[0036] In one embodiment, the appliance 205 provides application
and data acceleration services for branch-office or remote offices.
In one embodiment, the appliance 205 includes optimization of Wide
Area File Services (WAFS). In another embodiment, the appliance 205
accelerates the delivery of files, such as via the Common Internet
File System (CIFS) protocol. In other embodiments, the appliance
205 provides caching in memory and/or storage to accelerate
delivery of applications and data. In one embodiment, the appliance
205 provides compression of network traffic at any level of the
network stack or at any protocol or network layer. In another
embodiment, the appliance 205 provides transport layer protocol
optimizations, flow control, performance enhancements or
modifications and/or management to accelerate delivery of
applications and data over a WAN connection. For example, in one
embodiment, the appliance 205 provides Transport Control Protocol
(TCP) optimizations. In other embodiments, the appliance 205
provides optimizations, flow control, performance enhancements or
modifications and/or management for any session or application
layer protocol.
[0037] In another embodiment, the appliance 205 encoded any type
and form of data or information into custom or standard TCP and/or
IP header fields or option fields of network packet to announce
presence, functionality or capability to another appliance 205'. In
another embodiment, an appliance 205' may communicate with another
appliance 205' using data encoded in both TCP and/or IP header
fields or options. For example, the appliance may use TCP option(s)
or IP header fields or options to communicate one or more
parameters to be used by the appliances 205, 205' in performing
functionality, such as WAN acceleration, or for working in
conjunction with each other.
[0038] In some embodiments, the appliance 200 preserves any of the
information encoded in TCP and/or IP header and/or option fields
communicated between appliances 205 and 205'. For example, the
appliance 200 may terminate a transport layer connection traversing
the appliance 200, such as a transport layer connection from
between a client and a server traversing appliances 205 and 205'.
In one embodiment, the appliance 200 identifies and preserves any
encoded information in a transport layer packet transmitted by a
first appliance 205 via a first transport layer connection and
communicates a transport layer packet with the encoded information
to a second appliance 205' via a second transport layer
connection.
[0039] Referring now to FIG. 1D, a network environment for
delivering and/or operating a computing environment on a client 102
is depicted. In some embodiments, a server 106 includes an
application delivery system 190 for delivering a computing
environment or an application and/or data file to one or more
clients 102. In brief overview, a client 10 is in communication
with a server 106 via network 104, 104' and appliance 200. For
example, the client 102 may reside in a remote office of a company,
e.g., a branch office, and the server 106 may reside at a corporate
data center. The client 102 comprises a client agent 120, and a
computing environment 15. The computing environment 15 may execute
or operate an application that accesses, processes or uses a data
file. The computing environment 15, application and/or data file
may be delivered via the appliance 200 and/or the server 106.
[0040] In some embodiments, the appliance 200 accelerates delivery
of a computing environment 15, or any portion thereof, to a client
102. In one embodiment, the appliance 200 accelerates the delivery
of the computing environment 15 by the application delivery system
190. For example, the embodiments described herein may be used to
accelerate delivery of a streaming application and data file
processable by the application from a central corporate data center
to a remote user location, such as a branch office of the company.
In another embodiment, the appliance 200 accelerates transport
layer traffic between a client 102 and a server 106. The appliance
200 may provide acceleration techniques for accelerating any
transport layer payload from a server 106 to a client 102, such as:
1) transport layer connection pooling, 2) transport layer
connection multiplexing, 3) transport control protocol buffering,
4) compression and 5) caching. In some embodiments, the appliance
200 provides load balancing of servers 106 in responding to
requests from clients 102. In other embodiments, the appliance 200
acts as a proxy or access server to provide access to the one or
more servers 106. In another embodiment, the appliance 200 provides
a secure virtual private network connection from a first network
104 of the client 102 to the second network 104' of the server 106,
such as an SSL VPN connection. It yet other embodiments, the
appliance 200 provides application firewall security, control and
management of the connection and communications between a client
102 and a server 106.
[0041] In some embodiments, the application delivery management
system 190 provides application delivery techniques to deliver a
computing environment to a desktop of a user, remote or otherwise,
based on a plurality of execution methods and based on any
authentication and authorization policies applied via a policy
engine 195. With these techniques, a remote user may obtain a
computing environment and access to server stored applications and
data files from any network connected device 100. In one
embodiment, the application delivery system 190 may reside or
execute on a server 106. In another embodiment, the application
delivery system 190 may reside or execute on a plurality of servers
106a-106n. In some embodiments, the application delivery system 190
may execute in a server farm 38. In one embodiment, the server 106
executing the application delivery system 190 may also store or
provide the application and data file. In another embodiment, a
first set of one or more servers 106 may execute the application
delivery system 190, and a different server 106n may store or
provide the application and data file. In some embodiments, each of
the application delivery system 190, the application, and data file
may reside or be located on different servers. In yet another
embodiment, any portion of the application delivery system 190 may
reside, execute or be stored on or distributed to the appliance
200, or a plurality of appliances.
[0042] The client 102 may include a computing environment 15 for
executing an application that uses or processes a data file. The
client 102 via networks 104, 104' and appliance 200 may request an
application and data file from the server 106. In one embodiment,
the appliance 200 may forward a request from the client 102 to the
server 106. For example, the client 102 may not have the
application and data file stored or accessible locally. In response
to the request, the application delivery system 190 and/or server
106 may deliver the application and data file to the client 102.
For example, in one embodiment, the server 106 may transmit the
application as an application stream to operate in computing
environment 15 on client 102.
[0043] In some embodiments, the application delivery system 190
comprises any portion of the Citrix Access Suite.TM. by Citrix
Systems, Inc., such as the MetaFrame or Citrix Presentation
Server.TM. and/or any of the Microsoft.RTM. Windows Terminal
Services manufactured by the Microsoft Corporation. In one
embodiment, the application delivery system 190 may deliver one or
more applications to clients 102 or users via a remote-display
protocol or otherwise via remote-based or server-based computing.
In another embodiment, the application delivery system 190 may
deliver one or more applications to clients or users via steaming
of the application.
[0044] In one embodiment, the application delivery system 190
includes a policy engine 195 for controlling and managing the
access to, selection of application execution methods and the
delivery of applications. In some embodiments, the policy engine
195 determines the one or more applications a user or client 102
may access. In another embodiment, the policy engine 195 determines
how the application should be delivered to the user or client 102,
e.g., the method of execution. In some embodiments, the application
delivery system 190 provides a plurality of delivery techniques
from which to select a method of application execution, such as a
server-based computing, streaming or delivering the application
locally to the client 120 for local execution.
[0045] In one embodiment, a client 102 requests execution of an
application program and the application delivery system 190
comprising a server 106 selects a method of executing the
application program. In some embodiments, the server 106 receives
credentials from the client 102. In another embodiment, the server
106 receives a request for an enumeration of available applications
from the client 102. In one embodiment, in response to the request
or receipt of credentials, the application delivery system 190
enumerates a plurality of application programs available to the
client 102. The application delivery system 190 receives a request
to execute an enumerated application. The application delivery
system 190 selects one of a predetermined number of methods for
executing the enumerated application, for example, responsive to a
policy of a policy engine. The application delivery system 190 may
select a method of execution of the application enabling the client
102 to receive application-output data generated by execution of
the application program on a server 106. The application delivery
system 190 may select a method of execution of the application
enabling the local machine 10 to execute the application program
locally after retrieving a plurality of application files
comprising the application. In yet another embodiment, the
application delivery system 190 may select a method of execution of
the application to stream the application via the network 104 to
the client 102.
[0046] A client 102 may execute, operate or otherwise provide an
application, which can be any type and/or form of software,
program, or executable instructions such as any type and/or form of
web browser, web-based client, client-server application, a
thin-client computing client, an ActiveX control, or a Java applet,
or any other type and/or form of executable instructions capable of
executing on client 102. In some embodiments, the application may
be a server-based or a remote-based application executed on behalf
of the client 102 on a server 106. In one embodiments the server
106 may display output to the client 102 using any thin-client or
remote-display protocol, such as the Independent Computing
Architecture (ICA) protocol manufactured by Citrix Systems, Inc. of
Ft. Lauderdale, Fla. or the Remote Desktop Protocol (RDP)
manufactured by the Microsoft Corporation of Redmond, Wash. The
application can use any type of protocol and it can be, for
example, an HTTP client, an FTP client, an Oscar client, or a
Telnet client. In other embodiments, the application comprises any
type of software related to VoIP communications, such as a soft IP
telephone. In further embodiments, the application comprises any
application related to real-time data communications, such as
applications for streaming video and/or audio.
[0047] In some embodiments, the server 106 or a server farm 38 may
be running one or more applications, such as an application
providing a thin-client computing or remote display presentation
application. In one embodiment, the server 106 or server farm 38
executes as an application, any portion of the Citrix Access
Suite.TM. by Citrix Systems, Inc., such as the MetaFrame or Citrix
Presentation Server.TM., and/or any of the Microsoft.RTM. Windows
Terminal Services manufactured by the Microsoft Corporation. In one
embodiment, the application is an ICA client, developed by Citrix
Systems, Inc. of Fort Lauderdale, Fla. In other embodiments, the
application includes a Remote Desktop (RDP) client, developed by
Microsoft Corporation of Redmond, Wash. Also, the server 106 may
run an application, which for example, may be an application server
providing email services such as Microsoft Exchange manufactured by
the Microsoft Corporation of Redmond, Wash., a web or Internet
server, or a desktop sharing server, or a collaboration server. In
some embodiments, any of the applications may comprise any type of
hosted service or products, such as GoToMeeting.TM. provided by
Citrix Online Division, Inc. of Santa Barbara, Calif., WebEX.TM.
provided by WebEx, Inc. of Santa Clara, Calif., or Microsoft Office
Live Meeting provided by Microsoft Corporation of Redmond,
Wash.
[0048] Still referring to FIG. 1D, an embodiment of the network
environment may include a monitoring server 106A. The monitoring
server 106A may include any type and form performance monitoring
service 198. The performance monitoring service 198 may include
monitoring, measurement and/or management software and/or hardware,
including data collection, aggregation, analysis, management and
reporting. In one embodiment, the performance monitoring service
198 includes one or more monitoring agents 197. The monitoring
agent 197 includes any software, hardware or combination thereof
for performing monitoring, measurement and data collection
activities on a device, such as a client 102, server 106 or an
appliance 200, 205. In some embodiments, the monitoring agent 197
includes any type and form of script, such as Visual Basic script,
or Javascript. In one embodiment, the monitoring agent 197 executes
transparently to any application and/or user of the device. In some
embodiments, the monitoring agent 197 is installed and operated
unobtrusively to the application or client. In yet another
embodiment, the monitoring agent 197 is installed and operated
without any instrumentation for the application or device.
[0049] In some embodiments, the monitoring agent 197 monitors,
measures and collects data on a predetermined frequency. In other
embodiments, the monitoring agent 197 monitors, measures and
collects data based upon detection of any type and form of event.
For example, the monitoring agent 197 may collect data upon
detection of a request for a web page or receipt of an HTTP
response. In another example, the monitoring agent 197 may collect
data upon detection of any user input events, such as a mouse
click. The monitoring agent 197 may report or provide any
monitored, measured or collected data to the monitoring service
198. In one embodiment, the monitoring agent 197 transmits
information to the monitoring service 198 according to a schedule
or a predetermined frequency. In another embodiment, the monitoring
agent 197 transmits information to the monitoring service 198 upon
detection of an event.
[0050] In some embodiments, the monitoring service 198 and/or
monitoring agent 197 performs monitoring and performance
measurement of any network resource or network infrastructure
element, such as a client, server, server farm, appliance 200,
appliance 205, or network connection. In one embodiment, the
monitoring service 198 and/or monitoring agent 197 performs
monitoring and performance measurement of any transport layer
connection, such as a TCP or UDP connection. In another embodiment,
the monitoring service 198 and/or monitoring agent 197 monitors and
measures network latency. In yet one embodiment, the monitoring
service 198 and/or monitoring agent 197 monitors and measures
bandwidth utilization.
[0051] In other embodiments, the monitoring service 198 and/or
monitoring agent 197 monitors and measures end-user response times.
In some embodiments, the monitoring service 198 performs monitoring
and performance measurement of an application. In another
embodiment, the monitoring service 198 and/or monitoring agent 197
performs monitoring and performance measurement of any session or
connection to the application. In one embodiment, the monitoring
service 198 and/or monitoring agent 197 monitors and measures
performance of a browser. In another embodiment, the monitoring
service 198 and/or monitoring agent 197 monitors and measures
performance of HTTP based transactions. In some embodiments, the
monitoring service 198 and/or monitoring agent 197 monitors and
measures performance of a Voice over IP (VoIP) application or
session. In other embodiments, the monitoring service 198 and/or
monitoring agent 197 monitors and measures performance of a remote
display protocol application, such as an ICA client or RDP client.
In yet another embodiment, the monitoring service 198 and/or
monitoring agent 197 monitors and measures performance of any type
and form of streaming media. In still a further embodiment, the
monitoring service 198 and/or monitoring agent 197 monitors and
measures performance of a hosted application or a
Software-As-A-Service (SaaS) delivery model.
[0052] In some embodiments, the monitoring service 198 and/or
monitoring agent 197 performs monitoring and performance
measurement of one or more transactions, requests or responses
related to application. In other embodiments, the monitoring
service 198 and/or monitoring agent 197 monitors and measures any
portion of an application layer stack, such as any .NET or J2EE
calls. In one embodiment, the monitoring service 198 and/or
monitoring agent 197 monitors and measures database or SQL
transactions. In yet another embodiment, the monitoring service 198
and/or monitoring agent 197 monitors and measures any method,
function or application programming interface (API) call.
[0053] In one embodiment, the monitoring service 198 and/or
monitoring agent 197 performs monitoring and performance
measurement of a delivery of application and/or data from a server
to a client via one or more appliances, such as appliance 200
and/or appliance 205. In some embodiments, the monitoring service
198 and/or monitoring agent 197 monitors and measures performance
of delivery of a virtualized application. In other embodiments, the
monitoring service 198 and/or monitoring agent 197 monitors and
measures performance of delivery of a streaming application. In
another embodiment, the monitoring service 198 and/or monitoring
agent 197 monitors and measures performance of delivery of a
desktop application to a client and/or the execution of the desktop
application on the client. In another embodiment, the monitoring
service 198 and/or monitoring agent 197 monitors and measures
performance of a client/server application.
[0054] In one embodiment, the monitoring service 198 and/or
monitoring agent 197 is designed and constructed to provide
application performance management for the application delivery
system 190. For example, the monitoring service 198 and/or
monitoring agent 197 may monitor, measure and manage the
performance of the delivery of applications via the Citrix
Presentation Server. In this example, the monitoring service 198
and/or monitoring agent 197 monitors individual ICA sessions. The
monitoring service 198 and/or monitoring agent 197 may measure the
total and per session system resource usage, as well as application
and networking performance. The monitoring service 198 and/or
monitoring agent 197 may identify the active servers for a given
user and/or user session. In some embodiments, the monitoring
service 198 and/or monitoring agent 197 monitors back-end
connections between the application delivery system 190 and an
application and/or database server. The monitoring service 198
and/or monitoring agent 197 may measure network latency, delay and
volume per user-session or ICA session.
[0055] In some embodiments, the monitoring service 198 and/or
monitoring agent 197 measures and monitors memory usage for the
application delivery system 190, such as total memory usage, per
user session and/or per process. In other embodiments, the
monitoring service 198 and/or monitoring agent 197 measures and
monitors CPU usage the application delivery system 190, such as
total CPU usage, per user session and/or per process. In another
embodiments, the monitoring service 198 and/or monitoring agent 197
measures and monitors the time required to log-in to an
application, a server, or the application delivery system, such as
Citrix Presentation Server. In one embodiment, the monitoring
service 198 and/or monitoring agent 197 measures and monitors the
duration a user is logged into an application, a server, or the
application delivery system 190. In some embodiments, the
monitoring service 198 and/or monitoring agent 197 measures and
monitors active and inactive session counts for an application,
server or application delivery system session. In yet another
embodiment, the monitoring service 198 and/or monitoring agent 197
measures and monitors user session latency.
[0056] In yet further embodiments, the monitoring service 198
and/or monitoring agent 197 measures and monitors measures and
monitors any type and form of server metrics. In one embodiment,
the monitoring service 198 and/or monitoring agent 197 measures and
monitors metrics related to system memory, CPU usage, and disk
storage. In another embodiment, the monitoring service 198 and/or
monitoring agent 197 measures and monitors metrics related to page
faults, such as page faults per second. In other embodiments, the
monitoring service 198 and/or monitoring agent 197 measures and
monitors round-trip time metrics. In yet another embodiment, the
monitoring service 198 and/or monitoring agent 197 measures and
monitors metrics related to application crashes, errors and/or
hangs.
[0057] In some embodiments, the monitoring service 198 and
monitoring agent 198 includes any of the product embodiments
referred to as EdgeSight manufactured by Citrix Systems, Inc. of
Ft. Lauderdale, Fla. In another embodiment, the performance
monitoring service 198 and/or monitoring agent 198 includes any
portion of the product embodiments referred to as the TrueView
product suite manufactured by the Symphoniq Corporation of Palo
Alto, Calif. In one embodiment, the performance monitoring service
198 and/or monitoring agent 198 includes any portion of the product
embodiments referred to as the TeaLeaf CX product suite
manufactured by the TeaLeaf Technology Inc. of San Francisco,
Calif. In other embodiments, the performance monitoring service 198
and/or monitoring agent 198 includes any portion of the business
service management products, such as the BMC Performance Manager
and Patrol products, manufactured by BMC Software, Inc. of Houston,
Tex.
[0058] The client 102, server 106, and appliance 200 may be
deployed as and/or executed on any type and form of computing
device, such as a computer, network device or appliance capable of
communicating on any type and form of network and performing the
operations described herein. FIGS. 1E and 1F depict block diagrams
of a computing device 100 useful for practicing an embodiment of
the client 102, server 106 or appliance 200. As shown in FIGS. 1E
and 1F, each computing device 100 includes a central processing
unit 101, and a main memory unit 122. As shown in FIG. 1E, a
computing device 100 may include a visual display device 124, a
keyboard 126 and/or a pointing device 127, such as a mouse. Each
computing device 100 may also include additional optional elements,
such as one or more input/output devices 130a-130b (generally
referred to using reference numeral 130), and a cache memory 140 in
communication with the central processing unit 101.
[0059] The central processing unit 101 is any logic circuitry that
responds to and processes instructions fetched from the main memory
unit 122. In many embodiments, the central processing unit is
provided by a microprocessor unit, such as: those manufactured by
Intel Corporation of Mountain View, Calif.; those manufactured by
Motorola Corporation of Schaumburg, Ill.; those manufactured by
Transmeta Corporation of Santa Clara, Calif.; the RS/6000
processor, those manufactured by International Business Machines of
White Plains, N.Y.; or those manufactured by Advanced Micro Devices
of Sunnyvale, Calif. The computing device 100 may be based on any
of these processors, or any other processor capable of operating as
described herein.
[0060] Main memory unit 122 may be one or more memory chips capable
of storing data and allowing any storage location to be directly
accessed by the microprocessor 101, such as Static random access
memory (SRAM), Burst SRAM or SynchBurst SRAM (BSRAM), Dynamic
random access memory (DRAM), Fast Page Mode DRAM (FPM DRAM),
Enhanced DRAM (EDRAM), Extended Data Output RAM (EDO RAM), Extended
Data Output DRAM (EDO DRAM), Burst Extended Data Output DRAM (BEDO
DRAM), Enhanced DRAM (EDRAM), synchronous DRAM (SDRAM), JEDEC SRAM,
PC100 SDRAM, Double Data Rate SDRAM (DDR SDRAM), Enhanced SDRAM
(ESDRAM), SyncLink DRAM (SLDRAM), Direct Rambus DRAM (DRDRAM), or
Ferroelectric RAM (FRAM). The main memory 122 may be based on any
of the above described memory chips, or any other available memory
chips capable of operating as described herein. In the embodiment
shown in FIG. 1E, the processor 101 communicates with main memory
122 via a system bus 150 (described in more detail below). FIG. 1E
depicts an embodiment of a computing device 100 in which the
processor communicates directly with main memory 122 via a memory
port 103. For example, in FIG. 1F the main memory 122 may be
DRDRAM.
[0061] FIG. 1F depicts an embodiment in which the main processor
101 communicates directly with cache memory 140 via a secondary
bus, sometimes referred to as a backside bus. In other embodiments,
the main processor 101 communicates with cache memory 140 using the
system bus 150. Cache memory 140 typically has a faster response
time than main memory 122 and is typically provided by SRAM, BSRAM,
or EDRAM. In the embodiment shown in FIG. 1E, the processor 101
communicates with various I/O devices 130 via a local system bus
150. Various busses may be used to connect the central processing
unit 101 to any of the I/O devices 130, including a VESA VL bus, an
ISA bus, an EISA bus, a MicroChannel Architecture (MCA) bus, a PCI
bus, a PCI-X bus, a PCI-Express bus, or a NuBus. For embodiments in
which the I/O device is a video display 124, the processor 101 may
use an Advanced Graphics Port (AGP) to communicate with the display
124. FIG. 1F depicts an embodiment of a computer 100 in which the
main processor 101 communicates directly with I/O device 130 via
HyperTransport, Rapid I/O, or InfiniBand. FIG. 1F also depicts an
embodiment in which local busses and direct communication are
mixed: the processor 101 communicates with I/O device 130 using a
local interconnect bus while communicating with I/O device 130
directly.
[0062] The computing device 100 may support any suitable
installation device 116, such as a floppy disk drive for receiving
floppy disks such as 3.5-inch, 5.25-inch disks or ZIP disks, a
CD-ROM drive, a CD-R/RW drive, a DVD-ROM drive, tape drives of
various formats, USB device, hard-drive or any other device
suitable for installing software and programs such as any client
agent 120, or portion thereof. The computing device 100 may further
comprise a storage device 128, such as one or more hard disk drives
or redundant arrays of independent disks, for storing an operating
system and other related software, and for storing application
software programs such as any program related to the client agent
120. Optionally, any of the installation devices 116 could also be
used as the storage device 128. Additionally, the operating system
and the software can be run from a bootable medium, for example, a
bootable CD, such as KNOPPIX.RTM., a bootable CD for GNU/Linux that
is available as a GNU/Linux distribution from knoppix.net.
[0063] Furthermore, the computing device 100 may include a network
interface 118 to interface to a Local Area Network (LAN), Wide Area
Network (WAN) or the Internet through a variety of connections
including, but not limited to, standard telephone lines, LAN or WAN
links (e.g., 802.11, T1, T3, 56 kb, X.25), broadband connections
(e.g., ISDN, Frame Relay, ATM), wireless connections, or some
combination of any or all of the above. The network interface 118
may comprise a built-in network adapter, network interface card,
PCMCIA network card, card bus network adapter, wireless network
adapter, USB network adapter, modem or any other device suitable
for interfacing the computing device 100 to any type of network
capable of communication and performing the operations described
herein. A wide variety of I/O devices 130a-130n may be present in
the computing device 100. Input devices include keyboards, mice,
trackpads, trackballs, microphones, and drawing tablets. Output
devices include video displays, speakers, inkjet printers, laser
printers, and dye-sublimation printers. The I/O devices 130 may be
controlled by an I/O controller 123 as shown in FIG. 1E. The I/O
controller may control one or more I/O devices such as a keyboard
126 and a pointing device 127, e.g., a mouse or optical pen.
Furthermore, an I/O device may also provide storage 128 and/or an
installation medium 116 for the computing device 100. In still
other embodiments, the computing device 100 may provide USB
connections to receive handheld USB storage devices such as the USB
Flash Drive line of devices manufactured by Twintech Industry, Inc.
of Los Alamitos, Calif.
[0064] In some embodiments, the computing device 100 may comprise
or be connected to multiple display devices 124a-124n, which each
may be of the same or different type and/or form. As such, any of
the I/O devices 130a-130n and/or the I/O controller 123 may
comprise any type and/or form of suitable hardware, software, or
combination of hardware and software to support, enable or provide
for the connection and use of multiple display devices 124a-124n by
the computing device 100. For example, the computing device 100 may
include any type and/or form of video adapter, video card, driver,
and/or library to interface, communicate, connect or otherwise use
the display devices 124a-124n. In one embodiment, a video adapter
may comprise multiple connectors to interface to multiple display
devices 124a-124n. In other embodiments, the computing device 100
may include multiple video adapters, with each video adapter
connected to one or more of the display devices 124a- 124n. In some
embodiments, any portion of the operating system of the computing
device 100 may be configured for using multiple displays 124a-124n.
In other embodiments, one or more of the display devices 124a-124n
may be provided by one or more other computing devices, such as
computing devices 100a and 100b connected to the computing device
100, for example, via a network. These embodiments may include any
type of software designed and constructed to use another computer's
display device as a second display device 124a for the computing
device 100. One ordinarily skilled in the art will recognize and
appreciate the various ways and embodiments that a computing device
100 may be configured to have multiple display devices
124a-124n.
[0065] In further embodiments, an I/O device 130 may be a bridge
170 between the system bus 150 and an external communication bus,
such as a USB bus, an Apple Desktop Bus, an RS-232 serial
connection, a SCSI bus, a FireWire bus, a FireWire 800 bus, an
Ethernet bus, an AppleTalk bus, a Gigabit Ethernet bus, an
Asynchronous Transfer Mode bus, a HIPPI bus, a Super HIPPI bus, a
SerialPlus bus, a SCI/LAMP bus, a FibreChannel bus, or a Serial
Attached small computer system interface bus.
[0066] A computing device 100 of the sort depicted in FIGS. 1E and
1F typically operate under the control of operating systems, which
control scheduling of tasks and access to system resources. The
computing device 100 can be running any operating system such as
any of the versions of the Microsoft.RTM. Windows operating
systems, the different releases of the Unix and Linux operating
systems, any version of the Mac OS.RTM. for Macintosh computers,
any embedded operating system, any real-time operating system, any
open source operating system, any proprietary operating system, any
operating systems for mobile computing devices, or any other
operating system capable of running on the computing device and
performing the operations described herein. Typical operating
systems include: WINDOWS 3.x, WINDOWS 95, WINDOWS 98, WINDOWS 2000,
WINDOWS NT 3.51, WINDOWS NT 4.0, WINDOWS CE, and WINDOWS XP, all of
which are manufactured by Microsoft Corporation of Redmond, Wash.;
MacOS, manufactured by Apple Computer of Cupertino, Calif.; OS/2,
manufactured by International Business Machines of Armonk, N.Y.;
and Linux, a freely-available operating system distributed by
Caldera Corp. of Salt Lake City, Utah, or any type and/or form of a
Unix operating system, among others.
[0067] In other embodiments, the computing device 100 may have
different processors, operating systems, and input devices
consistent with the device. For example, in one embodiment the
computer 100 is a Treo 180, 270, 1060, 600 or 650 smart phone
manufactured by Palm, Inc. In this embodiment, the Treo smart phone
is operated under the control of the PalmOS operating system and
includes a stylus input device as well as a five-way navigator
device. Moreover, the computing device 100 can be any workstation,
desktop computer, laptop or notebook computer, server, handheld
computer, mobile telephone, any other computer, or other form of
computing or telecommunications device that is capable of
communication and that has sufficient processor power and memory
capacity to perform the operations described herein.
B. Appliance Architecture
[0068] FIG. 2A illustrates an example embodiment of the appliance
200. The architecture of the appliance 200 in FIG. 2A is provided
by way of illustration only and is not intended to be limiting. As
shown in FIG. 2, appliance 200 comprises a hardware layer 206 and a
software layer divided into a user space 202 and a kernel space
204.
[0069] Hardware layer 206 provides the hardware elements upon which
programs and services within kernel space 204 and user space 202
are executed. Hardware layer 206 also provides the structures and
elements which allow programs and services within kernel space 204
and user space 202 to communicate data both internally and
externally with respect to appliance 200. As shown in FIG. 2, the
hardware layer 206 includes a processing unit 262 for executing
software programs and services, a memory 264 for storing software
and data, network ports 266 for transmitting and receiving data
over a network, and an encryption processor 260 for performing
functions related to Secure Sockets Layer processing of data
transmitted and received over the network. In some embodiments, the
central processing unit 262 may perform the functions of the
encryption processor 260 in a single processor. Additionally, the
hardware layer 206 may comprise multiple processors for each of the
processing unit 262 and the encryption processor 260. The processor
262 may include any of the processors 101 described above in
connection with FIGS. 1E and 1F. In some embodiments, the central
processing unit 262 may perform the functions of the encryption
processor 260 in a single processor. Additionally, the hardware
layer 206 may comprise multiple processors for each of the
processing unit 262 and the encryption processor 260. For example,
in one embodiment, the appliance 200 comprises a first processor
262 and a second processor 262'. In other embodiments, the
processor 262 or 262' comprises a multi-core processor.
[0070] Although the hardware layer 206 of appliance 200 is
generally illustrated with an encryption processor 260, processor
260 may be a processor for performing functions related to any
encryption protocol, such as the Secure Socket Layer (SSL) or
Transport Layer Security (TLS) protocol. In some embodiments, the
processor 260 may be a general purpose processor (GPP), and in
further embodiments, may be have executable instructions for
performing processing of any security related protocol.
[0071] Although the hardware layer 206 of appliance 200 is
illustrated with certain elements in FIG. 2, the hardware portions
or components of appliance 200 may comprise any type and form of
elements, hardware or software, of a computing device, such as the
computing device 100 illustrated and discussed herein in
conjunction with FIGS. 1E and 1F. In some embodiments, the
appliance 200 may comprise a server, gateway, router, switch,
bridge or other type of computing or network device, and have any
hardware and/or software elements associated therewith.
[0072] The operating system of appliance 200 allocates, manages, or
otherwise segregates the available system memory into kernel space
204 and user space 204. In example software architecture 200, the
operating system may be any type and/or form of Unix operating
system although the invention is not so limited. As such, the
appliance 200 can be running any operating system such as any of
the versions of the Microsoft.RTM. Windows operating systems, the
different releases of the Unix and Linux operating systems, any
version of the Mac OS.RTM. for Macintosh computers, any embedded
operating system, any network operating system, any real-time
operating system, any open source operating system, any proprietary
operating system, any operating systems for mobile computing
devices or network devices, or any other operating system capable
of running on the appliance 200 and performing the operations
described herein.
[0073] The kernel space 204 is reserved for running the kernel 230,
including any device drivers, kernel extensions or other kernel
related software. As known to those skilled in the art, the kernel
230 is the core of the operating system, and provides access,
control, and management of resources and hardware-related elements
of the application 104. In accordance with an embodiment of the
appliance 200, the kernel space 204 also includes a number of
network services or processes working in conjunction with a cache
manager 232, sometimes also referred to as the integrated cache,
the benefits of which are described in detail further herein.
Additionally, the embodiment of the kernel 230 will depend on the
embodiment of the operating system installed, configured, or
otherwise used by the device 200.
[0074] In one embodiment, the device 200 comprises one network
stack 267, such as a TCP/IP based stack, for communicating with the
client 102 and/or the server 106. In one embodiment, the network
stack 267 is used to communicate with a first network, such as
network 108, and a second network 110. In some embodiments, the
device 200 terminates a first transport layer connection, such as a
TCP connection of a client 102, and establishes a second transport
layer connection to a server 106 for use by the client 102, e.g.,
the second transport layer connection is terminated at the
appliance 200 and the server 106. The first and second transport
layer connections may be established via a single network stack
267. In other embodiments, the device 200 may comprise multiple
network stacks, for example 267 and 267', and the first transport
layer connection may be established or terminated at one network
stack 267, and the second transport layer connection on the second
network stack 267'. For example, one network stack may be for
receiving and transmitting network packet on a first network, and
another network stack for receiving and transmitting network
packets on a second network. In one embodiment, the network stack
267 comprises a buffer 243 for queuing one or more network packets
for transmission by the appliance 200.
[0075] As shown in FIG. 2, the kernel space 204 includes the cache
manager 232, a high-speed layer 2-7 integrated packet engine 240,
an encryption engine 234, a policy engine 236 and multi-protocol
compression logic 238. Running these components or processes 232,
240, 234, 236 and 238 in kernel space 204 or kernel mode instead of
the user space 202 improves the performance of each of these
components, alone and in combination. Kernel operation means that
these components or processes 232, 240, 234, 236 and 238 run in the
core address space of the operating system of the device 200. For
example, running the encryption engine 234 in kernel mode improves
encryption performance by moving encryption and decryption
operations to the kernel, thereby reducing the number of
transitions between the memory space or a kernel thread in kernel
mode and the memory space or a thread in user mode. For example,
data obtained in kernel mode may not need to be passed or copied to
a process or thread running in user mode, such as from a kernel
level data structure to a user level data structure. In another
aspect, the number of context switches between kernel mode and user
mode are also reduced. Additionally, synchronization of and
communications between any of the components or processes 232, 240,
235, 236 and 238 can be performed more efficiently in the kernel
space 204.
[0076] In some embodiments, any portion of the components 232, 240,
234, 236 and 238 may run or operate in the kernel space 204, while
other portions of these components 232, 240, 234, 236 and 238 may
run or operate in user space 202. In one embodiment, the appliance
200 uses a kernel-level data structure providing access to any
portion of one or more network packets, for example, a network
packet comprising a request from a client 102 or a response from a
server 106. In some embodiments, the kernel-level data structure
may be obtained by the packet engine 240 via a transport layer
driver interface or filter to the network stack 267. The
kernel-level data structure may comprise any interface and/or data
accessible via the kernel space 204 related to the network stack
267, network traffic or packets received or transmitted by the
network stack 267. In other embodiments, the kernel-level data
structure may be used by any of the components or processes 232,
240, 234, 236 and 238 to perform the desired operation of the
component or process. In one embodiment, a component 232, 240, 234,
236 and 238 is running in kernel mode 204 when using the
kernel-level data structure, while in another embodiment, the
component 232, 240, 234, 236 and 238 is running in user mode when
using the kernel-level data structure. In some embodiments, the
kernel-level data structure may be copied or passed to a second
kernel-level data structure, or any desired user-level data
structure.
[0077] The cache manager 232 may comprise software, hardware or any
combination of software and hardware to provide cache access,
control and management of any type and form of content, such as
objects or dynamically generated objects served by the originating
servers 106. The data, objects or content processed and stored by
the cache manager 232 may comprise data in any format, such as a
markup language, or communicated via any protocol. In some
embodiments, the cache manager 232 duplicates original data stored
elsewhere or data previously computed, generated or transmitted, in
which the original data may require longer access time to fetch,
compute or otherwise obtain relative to reading a cache memory
element. Once the data is stored in the cache memory element,
future use can be made by accessing the cached copy rather than
refetching or recomputing the original data, thereby reducing the
access time. In some embodiments, the cache memory element may
comprise a data object in memory 264 of device 200. In other
embodiments, the cache memory element may comprise memory having a
faster access time than memory 264. In another embodiment, the
cache memory element may comprise any type and form of storage
element of the device 200, such as a portion of a hard disk. In
some embodiments, the processing unit 262 may provide cache memory
for use by the cache manager 232. In yet further embodiments, the
cache manager 232 may use any portion and combination of memory,
storage, or the processing unit for caching data, objects, and
other content.
[0078] Furthermore, the cache manager 232 includes any logic,
functions, rules, or operations to perform any embodiments of the
techniques of the appliance 200 described herein. For example, the
cache manager 232 includes logic or functionality to invalidate
objects based on the expiration of an invalidation time period or
upon receipt of an invalidation command from a client 102 or server
106. In some embodiments, the cache manager 232 may operate as a
program, service, process or task executing in the kernel space
204, and in other embodiments, in the user space 202. In one
embodiment, a first portion of the cache manager 232 executes in
the user space 202 while a second portion executes in the kernel
space 204. In some embodiments, the cache manager 232 can comprise
any type of general purpose processor (GPP), or any other type of
integrated circuit, such as a Field Programmable Gate Array (FPGA),
Programmable Logic Device (PLD), or Application Specific Integrated
Circuit (ASIC).
[0079] The policy engine 236 may include, for example, an
intelligent statistical engine or other programmable
application(s). In one embodiment, the policy engine 236 provides a
configuration mechanism to allow a user to identifying, specify,
define or configure a caching policy. Policy engine 236, in some
embodiments, also has access to memory to support data structures
such as lookup tables or hash tables to enable user-selected
caching policy decisions. In other embodiments, the policy engine
236 may comprise any logic, rules, functions or operations to
determine and provide access, control and management of objects,
data or content being cached by the appliance 200 in addition to
access, control and management of security, network traffic,
network access, compression or any other function or operation
performed by the appliance 200. Further examples of specific
caching policies are further described herein.
[0080] The encryption engine 234 comprises any logic, business
rules, functions or operations for handling the processing of any
security related protocol, such as SSL or TLS, or any function
related thereto. For example, the encryption engine 234 encrypts
and decrypts network packets, or any portion thereof, communicated
via the appliance 200. The encryption engine 234 may also setup or
establish SSL or TLS connections on behalf of the client 102a-102n,
server 106a-106n, or appliance 200. As such, the encryption engine
234 provides offloading and acceleration of SSL processing. In one
embodiment, the encryption engine 234 uses a tunneling protocol to
provide a virtual private network between a client 102a-102n and a
server 106a-106n. In some embodiments, the encryption engine 234 is
in communication with the Encryption processor 260. In other
embodiments, the encryption engine 234 comprises executable
instructions running on the Encryption processor 260.
[0081] The multi-protocol compression engine 238 comprises any
logic, business rules, function or operations for compressing one
or more protocols of a network packet, such as any of the protocols
used by the network stack 267 of the device 200. In one embodiment,
multi-protocol compression engine 238 compresses bi-directionally
between clients 102a-102n and servers 106a-106n any TCP/IP based
protocol, including Messaging Application Programming Interface
(MAPI) (email), File Transfer Protocol (FTP), HyperText Transfer
Protocol (HTTP), Common Internet File System (CIFS) protocol (file
transfer), Independent Computing Architecture (ICA) protocol,
Remote Desktop Protocol (RDP), Wireless Application Protocol (WAP),
Mobile IP protocol, and Voice Over IP (VoIP) protocol. In other
embodiments, multi-protocol compression engine 238 provides
compression of Hypertext Markup Language (HTML) based protocols and
in some embodiments, provides compression of any markup languages,
such as the Extensible Markup Language (XML). In one embodiment,
the multi-protocol compression engine 238 provides compression of
any high-performance protocol, such as any protocol designed for
appliance 200 to appliance 200 communications. In another
embodiment, the multi-protocol compression engine 238 compresses
any payload of or any communication using a modified transport
control protocol, such as Transaction TCP (T/TCP), TCP with
selection acknowledgements (TCP-SACK), TCP with large windows
(TCP-LW), a congestion prediction protocol such as the TCP-Vegas
protocol, and a TCP spoofing protocol.
[0082] As such, the multi-protocol compression engine 238
accelerates performance for users accessing applications via
desktop clients, e.g., Microsoft Outlook and non-Web thin clients,
such as any client launched by popular enterprise applications like
Oracle, SAP and Siebel, and even mobile clients, such as the Pocket
PC. In some embodiments, the multi-protocol compression engine 238
by executing in the kernel mode 204 and integrating with packet
processing engine 240 accessing the network stack 267 is able to
compress any of the protocols carried by the TCP/IP protocol, such
as any application layer protocol.
[0083] High speed layer 2-7 integrated packet engine 240, also
generally referred to as a packet processing engine or packet
engine, is responsible for managing the kernel-level processing of
packets received and transmitted by appliance 200 via network ports
266. The high speed layer 2-7 integrated packet engine 240 may
comprise a buffer for queuing one or more network packets during
processing, such as for receipt of a network packet or transmission
of a network packer. Additionally, the high speed layer 2-7
integrated packet engine 240 is in communication with one or more
network stacks 267 to send and receive network packets via network
ports 266. The high speed layer 2-7 integrated packet engine 240
works in conjunction with encryption engine 234, cache manager 232,
policy engine 236 and multi-protocol compression logic 238. In
particular, encryption engine 234 is configured to perform SSL
processing of packets, policy engine 236 is configured to perform
functions related to traffic management such as request-level
content switching and request-level cache redirection, and
multi-protocol compression logic 238 is configured to perform
functions related to compression and decompression of data.
[0084] The high speed layer 2-7 integrated packet engine 240
includes a packet processing timer 242. In one embodiment, the
packet processing timer 242 provides one or more time intervals to
trigger the processing of incoming, i.e., received, or outgoing,
i.e., transmitted, network packets. In some embodiments, the high
speed layer 2-7 integrated packet engine 240 processes network
packets responsive to the timer 242. The packet processing timer
242 provides any type and form of signal to the packet engine 240
to notify, trigger, or communicate a time related event, interval
or occurrence. In many embodiments, the packet processing timer 242
operates in the order of milliseconds, such as for example 100 ms,
50 ms or 25 ms. For example, in some embodiments, the packet
processing timer 242 provides time intervals or otherwise causes a
network packet to be processed by the high speed layer 2-7
integrated packet engine 240 at a 10 ms time interval, while in
other embodiments, at a 5 ms time interval, and still yet in
further embodiments, as short as a 3, 2, or 1 ms time interval. The
high speed layer 2-7 integrated packet engine 240 may be
interfaced, integrated or in communication with the encryption
engine 234, cache manager 232, policy engine 236 and multi-protocol
compression engine 238 during operation. As such, any of the logic,
functions, or operations of the encryption engine 234, cache
manager 232, policy engine 236 and multi-protocol compression logic
238 may be performed responsive to the packet processing timer 242
and/or the packet engine 240. Therefore, any of the logic,
functions, or operations of the encryption engine 234, cache
manager 232, policy engine 236 and multi-protocol compression logic
238 may be performed at the granularity of time intervals provided
via the packet processing timer 242, for example, at a time
interval of less than or equal to 10 ms. For example, in one
embodiment, the cache manager 232 may perform invalidation of any
cached objects responsive to the high speed layer 2-7 integrated
packet engine 240 and/or the packet processing timer 242. In
another embodiment, the expiry or invalidation time of a cached
object can be set to the same order of granularity as the time
interval of the packet processing timer 242, such as at every 10
ms.
[0085] In contrast to kernel space 204, user space 202 is the
memory area or portion of the operating system used by user mode
applications or programs otherwise running in user mode. A user
mode application may not access kernel space 204 directly and uses
service calls in order to access kernel services. As shown in FIG.
2, user space 202 of appliance 200 includes a graphical user
interface (GUI) 210, a command line interface (CLI) 212, shell
services 214, health monitoring program 216, and daemon services
218. GUI 210 and CLI 212 provide a means by which a system
administrator or other user can interact with and control the
operation of appliance 200, such as via the operating system of the
appliance 200 and either is user space 202 or kernel space 204. The
GUI 210 may be any type and form of graphical user interface and
may be presented via text, graphical or otherwise, by any type of
program or application, such as a browser. The CLI 212 may be any
type and form of command line or text-based interface, such as a
command line provided by the operating system. For example, the CLI
212 may comprise a shell, which is a tool to enable users to
interact with the operating system. In some embodiments, the CLI
212 may be provided via a bash, csh, tcsh, or ksh type shell. The
shell services 214 comprises the programs, services, tasks,
processes or executable instructions to support interaction with
the appliance 200 or operating system by a user via the GUI 210
and/or CLI 212.
[0086] Health monitoring program 216 is used to monitor, check,
report and ensure that network systems are functioning properly and
that users are receiving requested content over a network. Health
monitoring program 216 comprises one or more programs, services,
tasks, processes or executable instructions to provide logic,
rules, functions or operations for monitoring any activity of the
appliance 200. In some embodiments, the health monitoring program
216 intercepts and inspects any network traffic passed via the
appliance 200. In other embodiments, the health monitoring program
216 interfaces by any suitable means and/or mechanisms with one or
more of the following: the encryption engine 234, cache manager
232, policy engine 236, multi-protocol compression logic 238,
packet engine 240, daemon services 218, and shell services 214. As
such, the health monitoring program 216 may call any application
programming interface (API) to determine a state, status, or health
of any portion of the appliance 200. For example, the health
monitoring program 216 may ping or send a status inquiry on a
periodic basis to check if a program, process, service or task is
active and currently running. In another example, the health
monitoring program 216 may check any status, error or history logs
provided by any program, process, service or task to determine any
condition, status or error with any portion of the appliance
200.
[0087] Daemon services 218 are programs that run continuously or in
the background and handle periodic service requests received by
appliance 200. In some embodiments, a daemon service may forward
the requests to other programs or processes, such as another daemon
service 218 as appropriate. As known to those skilled in the art, a
daemon service 218 may run unattended to perform continuous or
periodic system wide functions, such as network control, or to
perform any desired task. In some embodiments, one or more daemon
services 218 run in the user space 202, while in other embodiments,
one or more daemon services 218 run in the kernel space.
[0088] Referring now to FIG. 2B, another embodiment of the
appliance 200 is depicted. In brief overview, the appliance 200
provides one or more of the following services, functionality or
operations: SSL VPN connectivity 280, switching/load balancing 284,
Domain Name Service resolution 286, acceleration 288 and an
application firewall 290 for communications between one or more
clients 102 and one or more servers 106. Each of the servers 106
may provide one or more network related services 270a-270n
(referred to as services 270). For example, a server 106 may
provide an http service 270. The appliance 200 comprises one or
more virtual servers or virtual internet protocol servers, referred
to as a vServer, VIP server, or just VIP 275a-275n (also referred
herein as vServer 275). The vServer 275 receives, intercepts or
otherwise processes communications between a client 102 and a
server 106 in accordance with the configuration and operations of
the appliance 200.
[0089] The vServer 275 may comprise software, hardware or any
combination of software and hardware. The vServer 275 may comprise
any type and form of program, service, task, process or executable
instructions operating in user mode 202, kernel mode 204 or any
combination thereof in the appliance 200. The vServer 275 includes
any logic, functions, rules, or operations to perform any
embodiments of the techniques described herein, such as SSL VPN
280, switching/load balancing 284, Domain Name Service resolution
286, acceleration 288 and an application firewall 290. In some
embodiments, the vServer 275 establishes a connection to a service
270 of a server 106. The service 275 may comprise any program,
application, process, task or set of executable instructions
capable of connecting to and communicating to the appliance 200,
client 102 or vServer 275. For example, the service 275 may
comprise a web server, http server, ftp, email or database server.
In some embodiments, the service 270 is a daemon process or network
driver for listening, receiving and/or sending communications for
an application, such as email, database or an enterprise
application. In some embodiments, the service 270 may communicate
on a specific IP address, or IP address and port.
[0090] In some embodiments, the vServer 275 applies one or more
policies of the policy engine 236 to network communications between
the client 102 and server 106. In one embodiment, the policies are
associated with a VServer 275. In another embodiment, the policies
are based on a user, or a group of users. In yet another
embodiment, a policy is global and applies to one or more vServers
275a-275n, and any user or group of users communicating via the
appliance 200. In some embodiments, the policies of the policy
engine have conditions upon which the policy is applied based on
any content of the communication, such as internet protocol
address, port, protocol type, header or fields in a packet, or the
context of the communication, such as user, group of the user,
vServer 275, transport layer connection, and/or identification or
attributes of the client 102 or server 106.
[0091] In other embodiments, the appliance 200 communicates or
interfaces with the policy engine 236 to determine authentication
and/or authorization of a remote user or a remote client 102 to
access the computing environment 15, application, and/or data file
from a server 106. In another embodiment, the appliance 200
communicates or interfaces with the policy engine 236 to determine
authentication and/or authorization of a remote user or a remote
client 102 to have the application delivery system 190 deliver one
or more of the computing environment 15, application, and/or data
file. In yet another embodiment, the appliance 200 establishes a
VPN or SSL VPN connection based on the policy engine's 236
authentication and/or authorization of a remote user or a remote
client 103 In one embodiment, the appliance 102 controls the flow
of network traffic and communication sessions based on policies of
the policy engine 236. For example, the appliance 200 may control
the access to a computing environment 15, application or data file
based on the policy engine 236. In some embodiments, the vServer
275 establishes a transport layer connection, such as a TCP or UDP
connection with a client 102 via the client agent 120. In one
embodiment, the vServer 275 listens for and receives communications
from the client 102. In other embodiments, the vServer 275
establishes a transport layer connection, such as a TCP or UDP
connection with a client server 106. In one embodiment, the vServer
275 establishes the transport layer connection to an internet
protocol address and port of a server 270 running on the server
106. In another embodiment, the vServer 275 associates a first
transport layer connection to a client 102 with a second transport
layer connection to the server 106. In some embodiments, a vServer
275 establishes a pool of transport layer connections to a server
106 and multiplexes client requests via the pooled transport layer
connections.
[0092] In some embodiments, the appliance 200 provides a SSL VPN
connection 280 between a client 102 and a server 106. For example,
a client 102 on a first network 102 requests to establish a
connection to a server 106 on a second network 104'. In some
embodiments, the second network 104' is not routable from the first
network 104. In other embodiments, the client 102 is on a public
network 104 and the server 106 is on a private network 104', such
as a corporate network. In one embodiment, the client agent 120
intercepts communications of the client 102 on the first network
104, encrypts the communications, and transmits the communications
via a first transport layer connection to the appliance 200. The
appliance 200 associates the first transport layer connection on
the first network 104 to a second transport layer connection to the
server 106 on the second network 104. The appliance 200 receives
the intercepted communication from the client agent 102, decrypts
the communications, and transmits the communication to the server
106 on the second network 104 via the second transport layer
connection. The second transport layer connection may be a pooled
transport layer connection. As such, the appliance 200 provides an
end-to-end secure transport layer connection for the client 102
between the two networks 104, 104'.
[0093] In one embodiment, the appliance 200 hosts an intranet
internet protocol or intranetIP 282 address of the client 102 on
the virtual private network 104. The client 102 has a local network
identifier, such as an internet protocol (IP) address and/or host
name on the first network 104. When connected to the second network
104' via the appliance 200, the appliance 200 establishes, assigns
or otherwise provides an IntranetIP, which is network identifier,
such as IP address and/or host name, for the client 102 on the
second network 104'. The appliance 200 listens for and receives on
the second or private network 104' for any communications directed
towards the client 102 using the client's established IntranetIP
282. In one embodiment, the appliance 200 acts as or on behalf of
the client 102 on the second private network 104. For example, in
another embodiment, a vServer 275 listens for and responds to
communications to the IntranetIP 282 of the client 102. In some
embodiments, if a computing device 100 on the second network 104'
transmits a request, the appliance 200 processes the request as if
it were the client 102. For example, the appliance 200 may respond
to a ping to the client's IntranetIP 282. In another example, the
appliance may establish a connection, such as a TCP or UDP
connection, with computing device 100 on the second network 104
requesting a connection with the client's IntranetIP 282.
[0094] In some embodiments, the appliance 200 provides one or more
of the following acceleration techniques 288 to communications
between the client 102 and server 106: 1) compression; 2)
decompression; 3) Transmission Control Protocol pooling; 4)
Transmission Control Protocol multiplexing; 5) Transmission Control
Protocol buffering; and 6) caching. In one embodiment, the
appliance 200 relieves servers 106 of much of the processing load
caused by repeatedly opening and closing transport layers
connections to clients 102 by opening one or more transport layer
connections with each server 106 and maintaining these connections
to allow repeated data accesses by clients via the Internet. This
technique is referred to herein as "connection pooling".
[0095] In some embodiments, in order to seamlessly splice
communications from a client 102 to a server 106 via a pooled
transport layer connection, the appliance 200 translates or
multiplexes communications by modifying sequence number and
acknowledgment numbers at the transport layer protocol level. This
is referred to as "connection multiplexing". In some embodiments,
no application layer protocol interaction is required. For example,
in the case of an in-bound packet (that is, a packet received from
a client 102), the source network address of the packet is changed
to that of an output port of appliance 200, and the destination
network address is changed to that of the intended server. In the
case of an outbound packet (that is, one received from a server
106), the source network address is changed from that of the server
106 to that of an output port of appliance 200 and the destination
address is changed from that of appliance 200 to that of the
requesting client 102. The sequence numbers and acknowledgment
numbers of the packet are also translated to sequence numbers and
acknowledgement expected by the client 102 on the appliance's 200
transport layer connection to the client 102. In some embodiments,
the packet checksum of the transport layer protocol is recalculated
to account for these translations.
[0096] In another embodiment, the appliance 200 provides switching
or load-balancing functionality 284 for communications between the
client 102 and server 106. In some embodiments, the appliance 200
distributes traffic and directs client requests to a server 106
based on layer 4 or application-layer request data. In one
embodiment, although the network layer or layer 2 of the network
packet identifies a destination server 106, the appliance 200
determines the server 106 to distribute the network packet by
application information and data carried as payload of the
transport layer packet. In one embodiment, the health monitoring
programs 216 of the appliance 200 monitor the health of servers to
determine the server 106 for which to distribute a client's
request. In some embodiments, if the appliance 200 detects a server
106 is not available or has a load over a predetermined threshold,
the appliance 200 can direct or distribute client requests to
another server 106.
[0097] In some embodiments, the appliance 200 acts as a Domain Name
Service (DNS) resolver or otherwise provides resolution of a DNS
request from clients 102. In some embodiments, the appliance
intercepts' a DNS request transmitted by the client 102. In one
embodiment, the appliance 200 responds to a client's DNS request
with an IP address of or hosted by the appliance 200. In this
embodiment, the client 102 transmits network communication for the
domain name to the appliance 200. In another embodiment, the
appliance 200 responds to a client's DNS request with an IP address
of or hosted by a second appliance 200'. In some embodiments, the
appliance 200 responds to a client's DNS request with an IP address
of a server 106 determined by the appliance 200.
[0098] In yet another embodiment, the appliance 200 provides
application firewall functionality 290 for communications between
the client 102 and server 106. In one embodiment, the policy engine
236 provides rules for detecting and blocking illegitimate
requests. In some embodiments, the application firewall 290
protects against denial of service (DoS) attacks. In other
embodiments, the appliance inspects the content of intercepted
requests to identify and block application-based attacks. In some
embodiments, the rules/policy engine 236 comprises one or more
application firewall or security control policies for providing
protections against various classes and types of web or Internet
based vulnerabilities, such as one or more of the following: 1)
buffer overflow, 2) CGI-BIN parameter manipulation, 3) form/hidden
field manipulation, 4) forceful browsing, 5) cookie or session
poisoning, 6) broken access control list (ACLs) or weak passwords,
7) cross-site scripting (XSS), 8) command injection, 9) SQL
injection, 10) error triggering sensitive information leak, 11)
insecure use of cryptography, 12) server misconfiguration, 13) back
doors and debug options, 14) website defacement, 15) platform or
operating systems vulnerabilities, and 16) zero-day exploits. In an
embodiment, the application firewall 290 provides HTML form field
protection in the form of inspecting or analyzing the network
communication for one or more of the following: 1) required fields
are returned, 2) no added field allowed, 3) read-only and hidden
field enforcement, 4) drop-down list and radio button field
conformance, and 5) form-field max-length enforcement. In some
embodiments, the application firewall 290 ensures cookies are not
modified. In other embodiments, the application firewall 290
protects against forceful browsing by enforcing legal URLs.
[0099] In still yet other embodiments, the application firewall 290
protects any confidential information contained in the network
communication. The application firewall 290 may inspect or analyze
any network communication in accordance with the rules or polices
of the engine 236 to identify any confidential information in any
field of the network packet. In some embodiments, the application
firewall 290 identifies in the network communication one or more
occurrences of a credit card number, password, social security
number, name, patient code, contact information, and age. The
encoded portion of the network communication may comprise these
occurrences or the confidential information. Based on these
occurrences, in one embodiment, the application firewall 290 may
take a policy action on the network communication, such as prevent
transmission of the network communication. In another embodiment,
the application firewall 290 may rewrite, remove or otherwise mask
such identified occurrence or confidential information.
[0100] Still referring to FIG. 2B, the appliance 200 may include a
performance monitoring agent 197 as discussed above in conjunction
with FIG. 1D. In one embodiment, the appliance 200 receives the
monitoring agent 197 from the monitoring service 1908 or monitoring
server 106 as depicted in FIG. 1D. In some embodiments, the
appliance 200 stores the monitoring agent 197 in storage, such as
disk, for delivery to any client or server in communication with
the appliance 200. For example, in one embodiment, the appliance
200 transmits the monitoring agent 197 to a client upon receiving a
request to establish a transport layer connection. In other
embodiments, the appliance 200 transmits the monitoring agent 197
upon establishing the transport layer connection with the client
102. In another embodiment, the appliance 200 transmits the
monitoring agent 197 to the client upon intercepting or detecting a
request for a web page. In yet another embodiment, the appliance
200 transmits the monitoring agent 197 to a client or a server in
response to a request from the monitoring server 198. In one
embodiment, the appliance 200 transmits the monitoring agent 197 to
a second appliance 200' or appliance 205.
[0101] In other embodiments, the appliance 200 executes the
monitoring agent 197. In one embodiment, the monitoring agent 197
measures and monitors the performance of any application, program,
process, service, task or thread executing on the appliance 200.
For example, the monitoring agent 197 may monitor and measure
performance and operation of vServers 275A-275N. In another
embodiment, the monitoring agent 197 measures and monitors the
performance of any transport layer connections of the appliance
200. In some embodiments, the monitoring agent 197 measures and
monitors the performance of any user sessions traversing the
appliance 200. In one embodiment, the monitoring agent 197 measures
and monitors the performance of any virtual private network
connections and/or sessions traversing the appliance 200, such an
SSL VPN session. In still further embodiments, the monitoring agent
197 measures and monitors the memory, CPU and disk usage and
performance of the appliance 200. In yet another embodiment, the
monitoring agent 197 measures and monitors the performance of any
acceleration technique 288 performed by the appliance 200, such as
SSL offloading, connection pooling and multiplexing, caching, and
compression. In some embodiments, the monitoring agent 197 measures
and monitors the performance of any load balancing and/or content
switching 284 performed by the appliance 200. In other embodiments,
the monitoring agent 197 measures and monitors the performance of
application firewall 290 protection and processing performed by the
appliance 200.
C. Clientless Virtual Private Network Environment
[0102] Referring now to FIG. 3A, an embodiment of a clientless
virtual private network (VPN) environment for accessing a server
via an appliance 200 or proxy is depicted. In brief overview, the
client 102 operates on computing device 100 and executes a browser
operated by a user. The client 102 may be on a first network 104,
such as a public network. A user on the client 102 may request via
the browser access to a resource on a second network 104', such as
a private network of an enterprise. The appliance 200 provides the
user a clientless VPN access to the requested resource. The client
may not install, execute or otherwise any agent, component,
program, driver or application that is constructed and/or designed
to provide VPN connectivity (referred to as client based VPN) to
the network 104'. Instead, the appliance or proxy may rewrite
responses from the server and requests from the client to provide
VPN functionality without the user of a VPN agent operating on the
client. For example, the appliance may rewrite Uniform Resource
Locators (URLs) between the client and server, such as URLs in any
content server by the server or requests transmitted by the client.
The appliance 200 may rewrite URLs between the client and the
server in a manner transparent and seamless to either or both of
the client and the server. As such, the client, browser or server
and server application do not need to have knowledge or be aware of
the clientless SSL VPN access scenario.
[0103] A virtual private network (VPN) may be any network using
public telecommunication infrastructure, such as the internet, to
provide remote clients, servers or other communicating devices with
an access or connection into a private network, such as from a
public network. A virtual private network (VPN) is a way to use a
public telecommunication infrastructure, such as the Internet, to
provide remote users with access to an enterprise or private
network. In some embodiments, the access is secure via encryption
or tunneling. In some embodiments, the intermediary described
herein provides a secure virtual private network connection from a
first network of the client to the second network of the
server.
[0104] A Secure Socket Layer (SSL) VPN may use SSL or TLS or any
other type and form of secure protocols to establish the connection
with a level of security. In some embodiments, an SSL VPN may use
any type and form of encryption for establishing or maintaining
secure access. An SSL VPN may be established and/or accessed via a
browser such as using HTTPS (Secure HyperText Transfer Protocol).
An SSL VPN may be established or provided by an SSL enabled browser
or application.
[0105] The SSL VPN connection or session may be established or
provided by either using a client based or clientless approach A
client based SSL VPN may be use any type and form of client agent
or any software related agent on the client 102 to establish a SSL
VPN connection or session. For example, a client based SSL VPN may
be provided via an SSL VPN client agent downloaded to the client,
such as downloaded from an appliance. The client agent may be
designed and configured to establish and provide the SSL VPN
functionality, connection and access between the client and the
appliance or server.
[0106] A clientless SSL VPN may be any SSL VPN that does not use an
SSL VPN client agent, software or programs downloaded and installed
on the client 102 to establish the SSL VPN connection or session.
In some embodiments, a clientless SSL VPN may be any SSL VPN that
does not require a client 102 to install or execute a predetermined
software or an executable file designed and constructed to provide
SSL VPN functionality in order to establish an SSL VPN connection
with another network device. In some embodiments, a clientless SSL
VPN is established via an SSL enabled browser that has not
downloaded or does not require the use of a VPN or SSL VPN client
agent. A clientless SSL VPN connection or session may use the
protocols and communications of a standard browser or application,
such as an SSL enabled browser. A clientless SSL VPN connection or
session may be provided by an intermediary or appliance as
described herein that translates, rewrites or transforms content of
requests and responses between a first network and a second
network.
[0107] The appliance 200 may provide via an SSL VPN 280 module,
previously described herein, a facility for accessing a resource.
In one embodiment, the appliance 200 provides a client based access
to a network by providing, installing or executing an SSL VPN agent
on the client 102 for communicating with the appliance 200. In some
embodiments, the appliance 200 provides for clientless SSL VPN
access to a resource, such as an http/https/file share, without
having to download an SSL VPN client or agent to the client 102.
For example, a user may want to access the resources within company
from an outside machine such at a kiosk on which he does not have
privilege to install the client or does not want to go through the
client installation process. The clientless SSL VPN feature is also
useful when the SSL VPN client is not supported for the device
(e.g. new PDA in market) but the device run an SSL enabled browser.
In other embodiments, the appliance 200 chooses for a user between
client-based and clientless SSL VPN access to the resource based on
policy and any policy rules, actions and/or conditions.
[0108] The client may include any type and form of user agent which
may be a browser, editor, spider (web-traversing robots), or any
other end user tool or program. The client 102 may include any type
and form of browser. In one embodiment, the browser is any version
of Internet Explorer manufactured by Microsoft Corporation of
Redmond, Wash. In another embodiment, the browser is any version of
the Netscape browser manufactured by the Netscape Communications
Corporation. In other embodiments, the browser is any version of
the open source browser referred to as Firefox and provided by
Mozilla Foundation of California and found at www.mozilla.com. In
yet another embodiment, the browser is any version of the browser
referred to as Opera manufactured by Opera Software ASA of Oslo,
Norway. In some embodiments, the client 102 executes or includes
any type and form of application or program for displaying web
pages, web content, HTML, XML, CSS (Cascading Style Sheets),
JavaScript or HTTP content.
[0109] In operation of the embodiment depicted by FIG. 3A, a user
logs in at the SSLVPN site provided by the appliance 200, such at a
domain name and IP address hosted by the appliance 200. For
example, the user via a browser of the client 102, may select or
enter a URL to the SSL VPN site. The appliance 200 may authenticate
the user and may further determine authorization of the user to
access the appliance 200 or the SSL VPN site. After successful
authentication, the appliance serves a portal page to the client to
display to the user via the browser. The portal page may include a
navigation box, such as a set of one or more user interface
elements for a user to select to operate or run an application. The
portal page may include links to other pages or URLs to which the
user may have access. The URLs or links on the portal page may
reference or identify the host name or IP address of the SSL VPN
site provided by the appliance 200.
[0110] The user via the portal page may select one or more URLs,
for example, by clicking on an active hyperlink or URL. In
response, the browser or client transmits a request to the domain
hosted by the appliance 200. For example, as depicted in FIG. 3A,
the user may request an application of the server 106 via the
appliance: "https://sslvpn.x.com/cvpn/http/server.x.com/app.cgi".
In some embodiments, the user sends another request, such as for
example "https://proxy.x.com/cvpn/http/server.x.com/app.cgi". The
appliance 200 receives the request from the client 102 and rewrites
the request to transmit to the server. For example, as depicted in
FIG. 3A, the appliance may remove or strip the domain name hosted
by the appliance such as "sslvpn.x.com" or "proxy.x.com" and
forward the remaining portion of the request to the server 106.
[0111] In response to the request, the server serves content to the
client. The content or body of the response may include embedded
links or URLs to other pages of the server or to other servers on
the network 104', such as embedded links to
"http://server.x.com/app.cgi". The appliance rewrites the header
and body to modify any URLs to reference the domain name or IP
address of the SSL VPN site so that any further URL or link
selection via the browser of the client communicates requests to
the appliance 200. The appliance communicates the modified content
to the client 102. The appliance 200, such as via the AppFw 290,
sometimes referred to as AppSecure module 290, may be designed and
constructed to rewrite URLs of requests and responses based on
policy of a policy engine. The links (URLs) in that page and other
pages received subsequently from the server during this SSL VPN
session are modified by the appliance in such a way that the links
point to the SSLVPN site (VPN VIP 275) and the original request URL
(absolute or relative) is encoded within that request URL.
[0112] Referring now to FIG. 3B, another embodiment of a VPN
environment for providing VPN access as well as cookie management
is depicted. In brief overview, the appliance 200 may include a VPN
module 280 for handling any of the SSL VPN functionality,
clientless and/or client based, as described herein. The appliance
and/or VPN module 280 may have an AAA module to perform any type
and form of authentication, authorization and auditing (AAA) and/or
to track and manage VPN session information. The AAA module may
also perform any type and form of VPN session look to determine the
VPN session for any client request. The VPN module may also perform
an URL decoding and covert the URL to server format, such as to
submit to a server on the private network. VPN module 280 also
includes DNS lookup functionality and authorization via VPN handler
function, logic or operation. The appliance may include a cookie
proxy or cookie manager for storing, tracking and managing cookies
between the client and the server. The cookie may include cookie
storage, referred to as a cookie jar for adding or inserting
cookies as well as removing cookies. The cookie manager or proxy
may include functions, logic or operations to store and look up
cookie information in a cookie jar by URL, domain name or other
information of the request and/or response. In some embodiments,
the appliance 200 manages cookies on the behalf of clients that do
not support cookies, disabled cookies or for cases where it may be
desired or preferred not to send cookies to the client.
[0113] The appliance may also include an AppFW 280 also referred to
as AppSecure in the context of an appliance manufactured by Citrix
Systems, Inc. The AppSecure 280 module may include logic, functions
or operations for perform any type and form of content rewriting,
such as URL rewriting. In some embodiments, the AppSecure 280
module performs any type and form of content injection into a
request and/or response between a client and a server. In one
embodiment, the AppSecure module 280 injects scripts into a
response to the client, such as a JavaScript, to perform any type
and form of desired functionality.
[0114] Any of the components of the appliance 200 used for
clientless SSL VPN access may be responsive to or driven by
configuration, such as via any one or more policies of the policy
engine. The policies may direct and determine the type and form of
URL encoding and decoding performed by the VPN module. In some
embodiments, the policies may direct and determine how and when the
cookie proxy manages and proxies cookies. In other embodiments, the
policies may direct and determine how and when the AppSecure module
performs URL rewriting and/or content injection. The policies may
direct the way a user access the private network and applications
on the private networks. Policies may be configured based on access
scenarios, which can include access based on any combination of a
user, type and form of client, type and form of network, type of
resources accessed, types of applications used, temporal
information as well as any information that may be determined by
the appliance via network traffic traversing thereto.
[0115] With reference to FIG. 3B, a flow of packets via the
appliance 200 for clientless SSL VPN access is discussed. In
response to a successful login request, the VPN appliance may send
a portal page to the sender of the login request. The portal page
may have one or more links in "vpn encoded form" as described in
connection with FIG. 3A. The portal page flows through the response
code path described below. When a user clicks on any of the URLs in
the portal page, the packet flow may be implemented in a number of
ways and using a number of steps. In some embodiments, for request
path at step Q1, the appliance 200 may receive a URL request and
look up the VPN session in the AAA module. At step Q2, the
appliance may decode the VPN encoded URL to the expected URL for
the server or the network 104'. The appliance may also modify the
header of the request, such as the header values, to server format,
or a format intended for transmission and use by the server 106,
such as the HTTP server for example. The appliance may reparse the
header so that any other modules of the appliance see the request
in the server format. At step Q3 in the request path, the appliance
via the cookie manager or proxy may look up the cookie for the
request based on the domain and path of the URL. In some cases, if
the request should include a cookie, the appliance may insert the
cookie from a cookie jar. At step Q4, the appliance may resolve the
domain name of the server present in the URL into an IP address of
the server via a DNS lookup function/module of the appliance. The
appliance may create server information based on the DNS lookup in
the AAA module. In addition, authorization policies may be
evaluated to determine if the request may be transmitted to the
server. At step Q5 the appliance may send the request to the
server. In some embodiments, the appliance sends the request to the
server provided that the authorization is successful.
[0116] In the response path from the server to the client via the
appliance, at step S1, the appliance may receive the response from
the server. The VPN module 280 may process the response. The VPN
module may pass the response header to the cookie proxy module and
the response body to the AppSecure module. At step S2, the cookie
proxy may remove cookies from the header of the response that are
not configured or otherwise identified as client consumed cookies
and store them in a cookie jar used for the current session. At
step S3, the AppSecure module may rewrite any URL in "vpn encoded
form" as per rewrite policies. The AppSecure module may also insert
into the response body any scripts, such as JavaScript code to be
executed at client side. At step S4, the appliance may send the
modified response to the client. In many embodiments, any of the Q
or S steps happen in any order or in any combination with any other
steps or embodiments described herein.
D. Systems and Methods For Configuration and Fine Grain Policy
Driven Web Content Detection and Rewrite
[0117] Referring now to FIG. 4, a view of a system for
configuration and policy driven web content detection and rewrite
is depicted. In brief overview, the system comprises the client 102
in communication with the appliance 200. In one embodiment, the
appliance 200 includes a policy engine 236, a SSL VPN module 280,
an URL rewriter 430 and a database 440. In another embodiment, the
policy engine further comprises clientless policies 405, client
based policies 410 and one or more access profiles 415A-415N (in
general referred to as access profiles 415). The appliance 200 is
in communication with the server 106. In one embodiment, one or
more applications 420a-420n (in general referred to as applications
420) execute on one or more servers 106. The client 102 transmits a
URL request 401 which is intercepted at the appliance 200. The
appliance 200 modifies the request 401 and forwards the modified
request 401' to the server 106.
[0118] In one embodiment, the request 401 transmitted by the client
102 includes a URL link for a SSL VPN site provided by the
appliance. In another embodiment, the request 401 is a URL request
for a site that is outside of the SSL VPN. In still another
embodiment, the request 401 includes authentication data required
to access the SSL VPN. In yet another embodiment, the request 401
is transmitted in response to the user accessing a link on a portal
page received at the client after successful authentication to the
SSL VPN. In some embodiments, the request 401 comprises a URL for
one or more of the following: web pages, static images, animated
images, audio files and video files. In some embodiments, the
request 401 comprises a URL accessing a resource, application or
service stored on one or more servers 106 on a secured network. The
request may include a URL for accessing resources, applications or
services that is different from, but associated with the URL that
the server 106 being accessed recognizes or accepts. In some
embodiments, the requests from the client 102 are rewritten,
modified or transformed before being forwarded to the server
106.
[0119] In some embodiments, the URL included in the request 401 may
be of the general form: <scheme name>:<hierarchical
part>[?<query>] The scheme name generally identifies the
protocol associated with the URL. The scheme name may include but
is not limited to the following: http (Hyper Text Transfer
protocol), https (Secure http), aaa (diameter protocol), aaas
(secure aaa), dns (Domain Name System), imap (Internet Message
Access Protocol), ftp (File Transfer Protocol), ldap (Lightweight
Directory Access Protocol), news (newsgroup protocol), telnet
(TELecommunication NETwork protocol), nntp (Network News Transfer
Protocol) and pop (Post Office Protocol). The URL may include any
type and form of portion of URL or URL related text, such as for
example: "http ://www.xyz.com/xyz/xyzpage.htm" or "ftp
://ftp.xyz.com/xyz/xyztext.txt",
"Idap://[1985:db8::7}/f=GB?objectClass?one".
[0120] The hierarchical part is intended to hold identification
information hierarchical in nature. In one embodiment the
hierarchical part begins with a double forward slash ("//"),
followed by an authority part. In some embodiment, the hierarchical
part contains path information locating a resource on the network.
In another embodiment, the authority part includes a hostname. In
still another embodiment, the authority part includes an optional
user information part terminated with "@" (e.g. username:password).
In one embodiment, the query part comprises information that is not
hierarchical in nature. In another embodiment, the fragment part
includes additional identifying information which allows indirect
identification of a secondary resource.
[0121] The appliance 200 may intercept the URL request 401 and pass
the request to the SSL VPN module 280. In one embodiment, the SSL
VPN module 280, in communication with the policy engine 236,
decides whether to rewrite the URL or not. In some embodiments, the
URL rewrite policies can be configured to provide a desired
granularity. In one of these embodiments with a finer level of
granularity, the SSN VPN module 280 decides whether the client 102
requesting access to the SSL VPN be granted clientless access or
client based access in response to a policy provided by the policy
engine 236. In some embodiments, the SSN VPN module decides on the
clientless access or client based access based on one or more
conditions of the policies 405 or 410. In one of these embodiments,
the client 102 may be a machine not allowing the user to download
the SSL VPN client. In another of these embodiments, the client 102
is a device that does not support the SSL VPN client but is enabled
to run a SSL enabled browser. In still another of these
embodiments, the SSL VPN module 280 may perform end point scanning
to determine that the client 102 does not support client based
policies 410 based on one or more of the following: incompatible
operating system, firewall and anti-virus software.
[0122] In some embodiments, the appliance 200 identifies a policy
based on any portion of the request 401. A request 401 may comprise
a portion that indicates or helps indicate the policy the appliance
200 will identify or choose. In some embodiments, the appliance 200
identifies a policy based on a header of the network packet. In
other embodiments, the appliance 200 identifies a policy based on a
payload portion of the network packet. In still other embodiments,
the appliance 200 identifies a policy based on another policy. In
one embodiment, the appliance 200 may act as a transparent proxy
based on an identified policy. In some embodiments the appliance
200 switches between policies to grant clientless or client based
access depending on a security condition of the network. By way of
example, in one embodiment, the appliance 200 may identify a policy
to grant clientless access if a presence of an antivirus software
or firewall is not detected, but switch to the client based mode
once the antivirus software or firewall is detected to be
operational.
[0123] The appliance 200 may identify a policy based on any detail,
information or indication from the request. In some embodiments,
the appliance 200 identifies a policy based on the user on the
client 102 that has sent the request. For example, a user may be
designated to use a clientless SSL VPN session instead of client
based SSL VPN sessions, or vice versa. In further embodiments, the
appliance 200 identifies a policy based on the application, the
resource or the service the client 102 has requested from the
server 106. For example, some applications are accessed by the
clients using only client based or clientless SSL VPN sessions. In
further embodiments, the appliance 200 identifies a policy based on
an information about the client 102. The information about the
client may comprise a history of client's interactions with the
server 106 or related servers, permissions for the client to access
specific resources on the server 106, client's authentication to
access specific resources on the server 106 or any other client to
server interaction related information. In some embodiments, the
appliance 200 identifies a policy based on the server 106 the
client 102 is accessing. For example, some servers may use or
provide client based SSL VPN sessions, while other may use or
provide clientless SSL VPN sessions. In some embodiments,
identification of a policy is based on any portion of a network
packet associated with the request 401. In some embodiments, the
appliance 200 identifies a policy based on one or more Regular
Expressions, or RegExs. In further embodiments, the client's
request is matched with, or compared against any number of RegExs
that may include any number of characters, strings, portions of
text or portions of URLs for identifying policies or identifying
specific URLs or portions of the request. Based on the results of
the matching or comparisons between the portions of the request
from the client and RegExs, the appliance 200 may identify the
policy.
[0124] In one embodiment, the clientless policies 405 may be
configured to provide a desired level of granularity. In one
embodiment, the clientless policies 405 may be configured based on
a user profile. In another embodiment, the policies 405 may be
configured based on a user or a group of users. In some
embodiments, the policies may be configured based on one or more of
a network type, IP address and request type. In some embodiments,
the policies 405 are configured based on an application, resource
or service being requested or being accessed by the client. In
further embodiments, the policies 405 are configured based on other
policies. In other embodiments, a plurality of policies may be
logically grouped together.
[0125] In one embodiment, the configuring is done through an
application programming interface (API) such as AppFW 290 also
referred to as AppSecure. In other embodiments, command line
interface (CLI) commands are used to configure clientless policies
405 of SSL VPN. In one of these embodiments, a CLI command such as
the following is used to configure the clientless SSL VPN
globally:
[0126] set vpn parameter-ClientLessVpnMode on
In another of these embodiments, the clientless SSL VPN provides a
finer granularity via a session action. In one embodiment, the
following CLI command can be used to enable the clientless SSL VPN
in a session action:
[0127] add vpn session action <actionname>-ClientLessVpnMode
on
[0128] In some embodiments, the clientless SSL VPN policies 405 are
configured to specify a URL encoding mechanism. In one of these
embodiments, the clientless policies 405 are configured to specify
a URL encoding mechanism at the global level using the following
CLI command:
[0129] set vpn param-ClientLessModeUrlEncoding
(opaque|transparent|encrypt)
In one embodiment, the `opaque` mode involves encoding of the
hostname portion of the URL such that the user does not see the
hostname in clear text. In another embodiment, the `transparent`
mode involves no encoding such that the user can see which host is
being accessed. In still another embodiment, the user can see both
the hostname and the path information of the URL in the
`transparent` mode. In yet another embodiment, the `encrypt` mode
involves encryption of one or more portion of the URL. In one
embodiment, the hostname and the path information are encrypted in
the `encrypt` mode. In another embodiment, the encryption is done
using a session key of a symmetric encryption mechanism. In still
other embodiments, the encryption can be done using a plurality of
encryption mechanism as apparent to one skilled in the art.
[0130] In some embodiments, the URL encoding mechanism is specific
to a session policy. In one of these embodiments, the URL encoding
mechanism may be configured specific to a user. In another of these
embodiments, the URL encoding mechanism may be configured specific
to a group. In still another of these embodiments, the URL encoding
mechanism can be configured specific to a virtual server (vserver).
In one embodiment, the URL can be configured specific to a session
policy as a parameter in the session policy's action. This may be
achieved using a CLI command such as:
TABLE-US-00001 add vpn session action <action name>
-ClientLessModeUrlEncoding (opaque | transparent | encrypt)
[0131] In some embodiments, finer granularity is provided in
clientless SSL VPN with the clientless policies 405 using one or
more access profiles 415. In one embodiment, an access profile 415
includes rewrite labels to instruct the rewriter 430 about
rewriting policies. Rewrite policies may include instructions to
rewrite or modify each URL from within the content or transmission
of the server 106 or the client 102 traversing the appliance 200.
For example, a rewrite policy for a specific URL may provide
instructions to rewrite, overwrite, modify or add any portion of
the URL from the content of the client 102 or server 106. In some
embodiments, a rewrite policy may provide instructions to exclude
or cut out any portion of the URL from the content of the client
102 or server 106. In another embodiment, the access profile 415
includes a pattern class (referred to as patclass) for detecting
URLs. In still another embodiment, the patclasses are comprised of,
or include Regular Expressions (RegEx). Regular Expressions may
include any combination of characters, numbers and symbols to be
used for detecting one or more URLs traversing the appliance 200.
In some embodiments, RegEx includes one or more portions or
sections of URLs or parts of the URLs to be used for detecting one
or more specific URLs within the content sent to the client 102 by
the server 106. In further embodiments, Regular Expressions include
text, scripts, characters and numbers used for matching against or
detecting one or more URLs within specific types of content. The
content may be any type and form of content provided by the server
106 to the client in response to the request of the client 102. In
yet another embodiment, the RegEx comprises a set of key
combinations to facilitate a variety of control over search strings
for URLs. In another embodiment, the access profile 415 includes
one or more patclasses containing names of cookies to be passed to
the client. In one embodiment, the access profile can be created
using a CLI command such as the following:
TABLE-US-00002 set vpn clientlessAccessProfile <profileName>
[-URLRewritePolicyLabel <string>]
[-JavaScriptRewritePolicyLabel <string>]
[-ReqHdrRewritePolicyLabel <string>]
[-ResHdrRewritePolicyLabel <string>]
[-RegexForFindingURLinJavaScript <string>]
[-RegexForFindingURLinCSS <string>]
[-RegexForFindingURLinXComponent <string>]
[-RegexForFindingURLinXML <string>] [-ClientConsumedCookies
<string>]
In another embodiment, the access profile 415 is linked to the
clientless access policies 405 to provide fine granularity. In
still another embodiment, the clientless access policy 405 is
linked to the access profile 415 using a CLI command such as the
following:
[0132] add vpn clientlessAccessPolicy
<policyName><rule><vpnclientlessAccessProfile>
The access policy 415 selects the access profile 415 if the rule
evaluates to TRUE.
[0133] In some embodiments, the access profile 415 is associated
with one or more of a plurality of applications 420a-420n (in
general referred to as applications 420). For example, access
profiles 415 maybe configured to a predetermined application 420.
In one embodiment, there may be one global access profile
configured for a group of applications 420. In another embodiment
each application 420 may have a separate access profile 415
associated with it. In still another embodiment, an access profile
415 associated with an application 420a is used for all versions of
the application 420a. In yet another embodiment, there may be
separate access profiles associated with each version of an
application 420a. In some embodiments there may be one or more
access profile 415 associated with another access profile 415. In
other embodiments access profiles could be specific to one or more
of a user, an application, a group of user and a group of
applications. In still other embodiments, access profiles 415 may
be configured according to a desired granularity level as apparent
to one skilled in the art.
[0134] In one embodiment, the application 420 is an email
application including but not limited to Outlook Web Access (OWA)
2003 and OWA 2007manufactured by Microsoft Corporation of Redmond,
Wash. In another embodiment, the application 420 can be a document
management platform such as Sharepoint 2007 manufactured by
Microsoft Corporation of Redmond, Wash. In still other embodiments,
the application 420 can be any other software or program as
apparent to one skilled in the art. In FIG. 4, all the applications
420 are shown to be executing on the server 106. In other
embodiments, the applications 420 may be executing on different
servers. In still other embodiments, the applications 420 may be
executing on one or more servers of a logically grouped server
farm.
[0135] In some embodiments, the SSL VPN clientless policies 405 are
bound to one or more VPN entities. In one embodiment, the
clientless policies 405 is bound to VPN global. In another
embodiment, the clientless policies 405 are bound to a VPN vserver.
In still another embodiment the clientless policies 405 are bound
to a user of Authentication, Authorization and Accounting (AAA)
protocol. In yet another embodiment, the clientless policies 405
are bound to a AAA group. In some embodiments, the clientless
policies 405 are bound to a VPN entity using a CLI command such as
the following:
[0136] bind <entity>-policy
<clientlessAccesspolicyName>-priority <pri>
[0137] In one embodiment, the SSL VPN module 280 communicates with
the URL rewriter 430 to inform the URL rewriter 430 about rewrite
policies obtained from the policy engine 236. In another
embodiment, the URL rewriter directly communicates with the policy
engine 236 to obtain rewrite policies. The rewrite policies may
include instructions or directions to transform, modify or
overwrite any specific URL transmitted by the server 106 or the
client 102. In some embodiments, the rewrite policies provide
instructions or directions to modify or rewrite a specific URL into
another URL. The modifications, changes or transformations may
include any combination of rewriting, overwriting, cutting and
pasting, encrypting, replacing or otherwise transforming a specific
URL, or any portion of the specific URL. In some embodiments, the
rewriter 430 rewrites the URL in the request 401 and forwards the
modified URL to the server 106. In one embodiment, the rewriter 430
rewrites the whole URL except the extension type of a file in order
to allow a browser to derive the MIME type. In another embodiment,
the rewriter 430 rewrites the hostname to make the hostname a
sub-directory under the SSL VPN site. In still another embodiment,
the rewriter rewrites the absolute URL keeping the relative URLs
unchanged. In yet another embodiment, the rewriter 430 rewrites the
hostname and the relative URLs. The rewriter 430 can do the
rewriting in one or more of a plurality of ways. In one embodiment,
the rewriter 430 encodes a URL such as http://www.unencoded_url.com
under a SSL VPN site such as http://www.sslvpn.com as
http://www.sslvpn.com/9oatj. In another embodiment, the rewriter
430 uses some session key to symmetrically encrypt and decrypt the
URL. Such encryption of URL is referred to as obfuscation. In one
embodiment, the file extension type and/or the SSL VPN hostname is
not encrypted by the rewriter 430. In another embodiment, the
rewriter 430 encrypts the path information to shield the directory
structure at the server. In one embodiment the key used for
encryption and decryption is provided by the SSL VPN module. In
another embodiment, the key is derived using a session id. By way
of example, a URL
http://www.unencoded_url.com/testsite/contents/file5.html is
encrypted to another URL such as:
https://svpn.mysite.com/EURL/whhyghfgdyonfdnv9898aaf.html. In one
embodiment, a known encoding and decoding scheme may be used in
order to facilitate bookmarking the URL for future SSL VPN
sessions. In another embodiment, the rewriter 430 rewrites an
original URL for a SSL VPN site using a reversible transformation.
In such an embodiment, the original URL can be easily extracted
from the rewritten URL. By way of example, a URL
http://www.xyz.com/htmil/index.html may be rewritten as the URL:
/cvpn/http/www.xyz.com/htmi/index.html.
[0138] The intermediary 200 may apply any of the access profiles,
policies, rules and actions to any level of granularity of portions
or subsets of network traffic traversing the intermediary 200. The
level of granularity may range from fine to coarse based on the
configuration. The logic, criteria or conditions of rules of access
profiles, rules and policies described herein may be defined or
specified to apply to any desired subset or portion of network
traffic or transmissions transmitted via the appliance 200. In one
aspect, the level of granularity refers to a degree, measurement,
fineness or coarseness of portions of network traffic to which the
configuration may apply. In very broad or coarse granularity of
configuration, an access profile, rule or a policy may apply to all
network traffic. In a very fine granularity configuration, an
access profile or policy may apply to a specific subset of network
traffic of a particular user, such a traffic or portions of traffic
of a particular application of a particular user. In some
granularity configurations, an access profile, policy or a rule
applies to any client 102 sending a request to a server. The
policy, rule or access profile may be defined to address, or apply
to any client 102, and may be based on any configuration of the
client 102 or information relating the client 102, such as for
example a portion the client 102 request. Similarly, the policy,
rule or access profile may be defined to address, or apply to any
server 106, and may be based on any configuration of the client 106
or information relating the server 106, such as for example a
portion the server 106 response. In some granularity
configurations, an access profile, policy or a rule is defined to
apply to a specific session or connection the client 102 is using
to connect to the server 106, via the appliance 200. In further
embodiments, an access profile, policy or a rule is defined to
apply to any client 102 the is connected via SSL VPN session or
connection. In further embodiments, an access profile, policy or a
rule is defined to apply to any client 102 that is connected via
clientless SSL VPN session or connection. In still further
embodiments, an access profile, policy or a rule is defined to
apply to any client 102 that is connected to via client based SSL
VPN session or connection. In still further embodiments, an access
profile, policy or a rule is defined to apply to any client 102 or
client session that sends a request to a particular server 106. In
yet further embodiments, an access profile, policy or a rule is
defined to apply to any client 102 or client session that requests
a particular application or a resource on the server. In further
embodiments, an access profile, policy or a rule is defined to
apply to any client 102 or client session based on the cookie
configuration, for example if the cookies are enabled or disabled.
In still further embodiments, an access profile, policy or a rule
is defined to apply to any client 102 or client session that sends
a request that includes a particular URL, or a portion of a
particular URL. In yet further embodiments, an access profile,
policy or a rule is defined to apply to any client 102 or client
session based on a match between a portion of the request sent by
the client 102 and a phrase or a key of the access profile, policy
or the rule. In some embodiments, an access profile, policy or a
rule is defined to apply to any server 106 or a server session
based on an information relating a client 102 accessing the server
106. Such information may include a portion or feature of the
request of the client 102, a setting or configuration of the client
102, or any other client 102 related information. In some
embodiments, an access profile, policy or a rule is defined to
apply to any server 106 or server session based on the
configuration of the server 106 or the features of the content that
the server 106 is transmitting to the client 102.
[0139] Referring now to FIG. 5, a flow diagram depicting the steps
of an embodiment of a method 500 taken at the appliance 200 to
perform URL rewriting is shown. The appliance 200 receives (step
510) URL request from a browser on a client. A SSL VPN module 280
residing on the appliance 200 decides (step 515) via policy whether
to provide clientless or client based access to the SSL VPN. The
policy engine 236 further determines (step 520) if there is an
access profile 415 associated with the request. The URL rewriter
430 residing on the appliance 200 rewrites (step 525) URLs
responsive to the access profile and/or policies. The appliance 200
forwards (step 530) the modified request to the server 106.
[0140] In one embodiment, the appliance 200 receives (step 510) the
URL request from a client over a network 104. In another
embodiment, the appliance 200 may reside on the client machine 102.
In one embodiment, the client's request, such as the request 401,
is received at the appliance 200 in response to a user accessing a
portal page provided by the appliance 200. The request may include
any type and form of content. In some embodiments, the URL request
includes any number of URLs. In further embodiments, the URL
request includes information about the user on the client 102. In
still further embodiments, the URL request includes information
about the client 102, such as security level of client's network
connection, security features of the client, user features or any
other type and form of information relating the client. In further
embodiments, the URL request includes information about the server
106 from whom the client 102 is requesting access to information,
service or resources.
[0141] The appliance 200 may determine (step 515) via policy
provided by a policy engine 236 whether to provide clientless or
client based access to SSL VPN. The clientless or client based SSL
VPN session may be a session between the client 102 and server 106
via appliance 200, between a client 102 and appliance 200, or
between appliance 200 and server 106. In one embodiment, the
clientless policies 405 provided by the policy engine 236 are
configurable. In one embodiment, the client based policies 410
provided by the policy engine 236 are configurable. In another
embodiment, the policy determining whether to give clientless or
client based access can also be configured. In one embodiment, the
determination can be done based on a part of the request 401. In
another embodiment, the determination to provide clientless access
is done if the client does not have permission or resources to
support client based access. In still another embodiment, the
appliance always determines to provide clientless access. In yet
another embodiment, the determination between clientless and client
based access is done based on one or more of the following: a
network packet of the request 401, a network condition, operating
system of the client and version thereof, a firewall, anti virus
software running on the client and the browser of the client. In
some embodiments, appliance 200 identifies a session policy that
indicates whether to establish a client based or clientless SSL VPN
session based on the application requested by the client 102. In
further embodiments, the appliance identifies a session policy that
indicates whether to establish a client based or clientless SSL VPN
session based on a URL from the request of the client 102. The URL
used for identifying the session policy may be detected and
identified by an access profile 415, or RegEx of an access profile
415. In some embodiments, appliance 200 identifies a session policy
that indicates whether to establish a client based or clientless
SSL VPN session based on the user on the client 102. The user on
the client 102 may have special privileges or constraints that
appliance 200 recognizes and identifies for the user a session
policy for client based or via clientless SSL VPN sessions
depending on such configuration. In some embodiments, appliance 200
identifies a session policy that indicates whether to establish a
client based or clientless SSL VPN session based on an information
relating the client 102. In some embodiments, the information may
include identification of the client 102, such as an internet
protocol (IP) address, a hostname, a name of the network via which
the client 102 sends the request, a name of the client 102's
internet provider, or any other client 102 related information. In
some embodiments, appliance 200 identifies a session policy that
indicates whether to establish a client based or clientless SSL VPN
session based on the server identified by the request of the client
102. In yet further embodiments, appliance 200 identifies a session
policy that indicates whether to establish a client based or
clientless SSL VPN session based on a type of the resource or
service of the server 106 requested by the client 102. In still
further embodiments, appliance 200 identifies a session policy that
indicates whether to establish a client based or clientless SSL VPN
session based on the specific resource or service of the server 106
requested by the client 102.
[0142] In some embodiments, an access profile 415 is associated
with the request 401. In one embodiment, the policy engine 236
determines (step 520) which access profile should be invoked for a
request 401. The access profile 415 may be invoked based on the
identification of the session policy or based on the request of the
client 102. In one embodiment, the determination is based on a part
of the request 401. For example, the appliance 200 determines from
a header and/or a portion of a body of the request the policy 405
or 410 to use and/or the access profiles 415 to use. In some
embodiments, an access profile 415 is identified based on a RegEx
of the access profile 415. In further embodiments, a RegEx of an
access profile 415 is matched to a URL or a portion of the URL from
the client's request, and in response to the match, the access
profile 415 of the matched RegEx is identified. In another
embodiment, determination of the access profile is based on the
application 420 requested by the URL request 401. In still another
embodiment, the policy engine determines to invoke more than one
access profiles 415 for a request 401. In one embodiment, the
access profile 415 provides rewrite policies to the rewriter 430.
In another embodiment, the access profile provides policies of
parsing the request to detect URLs. In some embodiments, there is
an in-built default profile. In one of these embodiments, the
default profile is selected if the access policies do not select
any other profile.
[0143] In one embodiment, the URL rewriter residing on the
appliance 200 rewrites (step 525) URLs as dictated by the policy
engine. In another embodiment, the rewrite policies are present in
the access profiles 415. The rewrite policy may be a part of an
access profile 415 that is identified by matching a RegEx to URL or
a portion of the URL of the client's request. In still another
embodiment, rewrite policies are present in the policy engine as a
separate entity. In some embodiments, rewrite policies specify what
type of content is to be rewritten. The content type may be
generally referred to as transform type. In one embodiment, the
transform type is a URL. In another embodiment, the transform type
is text. In still another embodiment, the transform type is a http
request (http req). In yet another embodiment, the transform type
is a http response (http_res). In one embodiment, rewrite policies
can be added to existing ones using a CLI command such as the
following:
[0144] add rewrite policylabel
<labelName><transform>
In another embodiment, rewrite actions can be specified with more
granularity using a CLI command such as the following:
TABLE-US-00003 add rewrite action <action-name>
clientless_vpn_encode/clientless_vpn_decode/
clientless_vpn_encode_all/clientless_vpn_decode_all
<target>
[0145] The appliance 200 forwards (step 530) the modified request
to the server 106. In one embodiment, the appliance 200 forwards
the modified request to the server 106 over a network 104' which
may or may not be substantially same as the network 104 between the
client and the appliance. In another embodiment, the appliance 200
forwards the modified request via one or more intermediate
appliances 200' (not shown).
[0146] Referring now to FIG. 6, a block diagram depicting
embodiments of a server response and a modified server response
transmitted from a server to a client through an appliance is
shown. In brief overview, a server response 601 is transmitted from
the server 106 to the appliance 200 via a network 104'. The
appliance 200 modifies the server response 601 by rewriting URLs in
the server response 601. A modified response 601' is then
transmitted to the client 102 via a network 104.
[0147] The server response 601 is transmitted from the server 106
responsive to the server 106 receiving the modified request 401'
(not shown) from the appliance 200. The server response 601 may be
any response to any client 102 transmission or request. In some
embodiments, server response 601 is a response to request 401. The
server response 601 may comprise one or more of the following
resources: static images, animated images, audio files and video
files. In one of these embodiments, the static image is a raster
graphic format such as GIF, JPEG or PNG. In another of these
embodiments, the static image is a vector format such as SVG Flash.
In still another embodiment, the animated image is an animated GIF
image, a Java applet or a Shockwave image. In yet another
embodiment, the audio file may be of one of a plurality of formats
including MIDI, WAV, M3U and MP3. In another embodiment, the video
file may be of one of a plurality of formats including WMV, RM,
FLV, MPG and MOV. In one embodiment, the server response 601 may
comprise interactive text, illustrations and buttons. In some
embodiments the one or more resources of the server response 601
are identified by URLs. In one embodiment, on or more URLs 605 is
created using a markup language such as XML, HTML or XHTML. In
another embodiment, one or more URLs 610 in the server response 601
comprises a cascading style sheet (CSS) and metadata. In still
another embodiment, one or more URLs 620 in the server response 601
comprises a script such as JavaScript or AJAX. In yet another
embodiment, one or more URLs (615) in the server response 601
comprises components (Xcomponents) written using an user interface
(UI) language.
[0148] The appliance 200 identifies the various URLs 605, 610, 615,
620 in the server response 601 and rewrites, modifies or transforms
the URLs in accordance to rewrite policies specified by the policy
engine 236 such as via the access profile. The various URLs in the
server response 601 may be identified or detected using Regular
Expressions that may be matched to the portions of any of the
various URLs. In one embodiment, the modified server response 601'
is then transmitted to the client 102 over the network 104. In
another embodiment, the modified server response 601' comprises URL
605' created by modifying the markup language URL 605. In still
another embodiment, the modified server response 601' comprises URL
610' created by modifying the CSS URL 610. In yet another
embodiment, the modified response 601' includes a URL 615' created
by modifying the Xcomponent URL 615. In another embodiment, the
modified response 601' includes a URL 620' created by rewriting a
JavaScript URL 620. In other embodiments, the modified response may
include other components, script and objects as apparent to one
skilled in the art. In one embodiment, the appliance 200 may inject
content not present in the server response 601 into the modified
response 601'. In another embodiment, the modified response 601'
may be substantially same as the server response 601.
[0149] Referring now to FIG. 7, a flow diagram depicting steps of
an embodiment of a method for modifying or rewriting one or more
URLs on a server response, by an appliance, is illustrated. The
appliance 200 receives (step 710) the server response 601. The
policy engine determines (step 715) the types of content present in
the server response 601 and determines via access profiles 415 how
to detect URLs in the content. The policy engine further determines
(step 720) via access profile how to rewrite the URLs. The rewriter
430 rewrites (step 725) URLs and the appliance 200 forwards (step
730) modified response to the client 102.
[0150] In one embodiment, the server response 601 comprises
different types of contents. In one embodiment, the server response
includes contents created using a mark up language such as
Extensible Markup Language (XML), Hypertext Markup Language (HTML)
or Extensible HTML (XHTML). In another embodiment, the server
response 601 includes a cascading style sheet (CSS) and metadata.
In still another embodiment, the server response 601 includes a
script such as JavaScript or AJAX. In yet another embodiment, the
server response 601 comprises components (Xcomponents) written
using an user interface (UI) language. In other embodiments, the
server response may comprise files, objects, images, videos and
interactive contents as apparent to one skilled in the art. In some
embodiments, the server response 601 includes a server provided
application requested by the client 102. In further embodiments,
the server response 601 includes any resource or service requested
by the client 102.
[0151] In one embodiment, the server response 601 is received (step
710) at the appliance over a network 104'. In another embodiment,
the server response 601 comprises one or more resources identified
by one or more URLs. The server response may include one or more of
a plurality of resources as described in details with reference to
FIG. 6.
[0152] The appliance 200, in communication with the policy engine
236, determines (step 715) the type of content present in the
response 601. In one embodiment, the determination is done by
parsing the response and detecting the presence of a type of
content. In another embodiment, the determination is done by
matching a search string pattern class (patclass) with the response
601. In one embodiment, the appliance 200 detects the presence of
embedded URLs in the determined content types. In another
embodiment, URL detection is done via a set of key combinations
known as Regular Expressions (RegEx) to facilitate variety of
control over the search string. In some embodiments, the RegEx are
embedded inside the clientless access profile 415. RegEx may
include any combination of any characters, numbers and symbols that
may be used for matching with any section of server content to
detect or identify one or more URLs. In one embodiment, the access
profile 415 comprises a RegEx for detecting URL in JavaScript. In
another embodiment, the access profile 415 comprises a RegEx for
detecting URL in CSS. In still another embodiment, the access
profile 415 comprises a RegEx for detecting URL in an Xcomponent.
In yet another embodiment, the access profile 415 includes a RegEx
for detecting URL in a markup language such as XML. Access profile
415 may include one or more RegEx and rewrite policies for
detecting or identifying specific URLs and rewriting or modifying
the identified specific URLs. In one embodiment a RegEx can be
specified inside an access profile 415 using a CLI command such as
the following:
[0153] [-RegexForFindingURLinJavaScript <string>]
In some embodiments, the user may define rules to detect URLs in
contents not identified by the appliance. In other embodiments, the
user may specify a RegEx to detect URL within an identified content
type.
[0154] The rewriter 430 may rewrite the detected or identified
URLs(step 725) in accordance to a policy specified by the policy
engine 236. In some embodiments, the rewriter 430 uses one or more
rewrite policies from the access profile 415 to rewrite the URLs
detected or identified via RegExs from access profiles 415. In one
embodiment, the rewrite policy is embedded in an access profile
415. In another embodiment, a rewrite policy for the response may
be different from a rewrite policy for the request. In still
another embodiment, the rewrite policies for the response and the
request may be substantially same. In yet another embodiment, the
body of the response 601 is parsed by an application programming
interface such as AppFW 290. In one embodiment, the policies
governing the rewrite are added to the policy engine 236 by using a
CLI command such as the following:
[0155] Add rewrite PolicyLabel <string>]
In another embodiment, the policy engine specifies to the rewriter
430 to pass certain URLs without rewriting. In still another
embodiment fine granularity can be provided by logically grouping a
plurality of conditions in a rewrite policy. By way of example, a
fine grained rewrite policy may be represented by a CLI command
such as the following:
TABLE-US-00004 add rewrite policy ns_cvpn_default_abs_url_pol
`(url.startswith("http://") || url.startswith("https://"))
&& !url.hostname.server.startswith("schemas.") &&
!url.hostname.domain.contains_any-
("ns_cvpn_default_bypass_domain")`
ns_cvpn_default_url_encode_act
[0156] In this example, the policy ns_cvpn_default_abs_url_pol is
used to rewrite all the absolute URLs in which server name is not
"schemas" and domain does not match with any of the domains
specified in ns_cvpn_default_bypass_domain patclass. In some
embodiments, rewriting is performed at the client 102. In one of
these embodiments, the appliance 200 inserts JavaScript code in the
modified response 601' to be executed at the client 102'. In
another of these embodiments, client side rewriting is invoked for
parts of the response that the appliance 200 cannot recognize as
URL. In still other embodiments, the rewrite policies can be
configured to handle compressed content in the server response
601.
[0157] Some CLI commands are described next by way of examples. In
one embodiment, an administrator can specify how to identify an
application such as OWA 2007 using a CLI command such as the
following:
TABLE-US-00005 add vpn clientlessAccessPolicy owa_2007_pol
`http.req.url.path.get(1).eq("owa2007")` ns_cvpn_owa_profile
In another embodiment, this policy can be activated globally by
binding it to vpn global using a CLI command such as the
following:
[0158] bind vpn global-policy owa.sub.--2007_pol-priority 10
[0159] In one embodiment, there will be an in-built profile
ns_cvpn_owa_profile for Outlook Web Access and same profile will
work for OWA 2003 & OWA 2007. In another embodiment, there will
be a default clientless access policy ns_cvpn_owa_policy which will
select the OWA profile if default URLs (/exchange, /owa, /exchweb
& /public) are used to provide Outlook Web Access. In still
another embodiment, there will be an in-built generic profile for
clientless access ns_cvpn_default_profile, this profile will be
selected if none of the other clientless access policies select any
other profile. This default profile will enable clientless access
to any website which uses standard HTML and does not create URLs
using JavaScript.
[0160] The appliance 200 may forward (step 730) the modified
response 601' to the client 102. In some embodiments, appliance 200
forwards any number of modified responses 601' to any number of
clients 102. In further embodiments, appliance 200 forwards server
response 601 to the client. In still further embodiments, appliance
200 forwards to the client 102 the modified response 601' which was
modified or transformed to include all of the content of the server
response 601 with changes or modifications to the specific URLs,
such as URLs 605, 610, 615 and 620, for example. The content of the
modified response 601' may include any portions of the response 601
along with modified URLs which were identified or detected using
one or more RegExs and modified or rewritten using rewrite policies
of the access profiles 415.
* * * * *
References